Opening Moves on the Southwest Front
On the 23rd of May 1915 the Italian Ambassador had presented his government's declaration of war on the Habsburg state at the Ballhausplatz. The aged Emperor and King Franz Joseph announced this momentous turn of events to his people. He complained bitterly of Italy's breach of faith, unable to contain his anger for an ally of thirty years standing who had sold out to the highest bidder - the Entente powers in the hope of gaining territory at Austria's expense. Italy was of course the hereditary enemy of the Habsburg monarchy and certainly no new opponent of the empire. The Emperor invoked memories of past victories: Novara, Mortara, Custoza and Lissa and of the spirit of Austria's former heroes: Field Marshal Radetzky, Archduke Albrecht and Admiral Tegethoff.
Not only did the German population of Austria proper appreciate the danger to the Tyrol, that most loyal of Austrian provinces but the fact that Bozen, German for centuries and also Trient and Triest were also in Italy's sight. The Hungarians, always troublesome partners in the monarchy were equally outraged by Italy's conduct. Even greater was the animosity shown to Italy by the peoples of Slovenia and Dalmatia who would be the most affected by any Italian territorial gains in Carniola and on the Adriatic coast.
Austria's situation at this time was extremely delicate. Although the fortunes of war appeared to be turning favorably on the Northeast front after the successful battle earlier that month at Gorlice-Tarnow, there could be little doubt that the overall situation of the monarchy had worsened both politically and economically and of course militarily. The strength of the Italian army was assumed by the Austro-Hungarian high command to be 44 infantry and 4 cavalry divisions. This was not an altogether inaccurate estimate. But regardless of the strength of the Italians, the Austro-Hungarians were only able to deploy a fraction of their own strength due to commitments on the Northeastern and Serbian fronts. When war was declared the monarchy had 128 mainly militia and reserve battalions deployed on the border. A further 94 battalions were en-route as the first reinforcement echelon. It was certainly expected, that after months of preparation, the Italians would speedily take the offensive.
At the k.u.k. Heeresleitung in Teschen it was presumed that of the Italian forces, 9 infantry and 2 cavalry divisions including 10 Alpini battalions would be deployed as the main assault group on the Adriatic coastland, 2½ divisions and 15 Alpini battalions on the Carinthian border, 3 divisions in Cadore, 9½ divisions opposite the South Tyrolean bastion and a further 2 cavalry divisions between Tagliamento and Livenza. All in all, this forecast proved to be quite realistic. Of the 16 unaccounted for divisions, the k.u.k. general staff thought that 7 were earmarked for expedition use in Ancona, Bari and Brindisi, 2 were on the Swiss frontier and 2 in Libya. They were unable to account for the remaining 5 divisions. The command of the Southwest front was established on the 28th of May under the command of General der Infanterie Archduke Eugen. His mission: "To defend the Tyrol from the foreign invading enemy with the troops in place and to hinder the enemies advance in Carinthia, the Adriatic coastland and Carniola with the smallest possible loss of own territory and to subsequently endeavour to strike the enemy an extensive a blow as possible."
Italy's Plans
The Italian Chief of Staff General Luigi Cadorna had at the 1st April 1915 deployed from West to East the following forces at his command:
1st Army (Verona): Lieutenant General Roberto Brusati with III Corps (Milan),a reinforced brigade from the garrison of verona and V Corps (Verona). They were to remain on the strategic defensive in the area running from the junction with the Swiss and Austrian borders at the Stilfser Joch and as far East as the Cismon Valley.
4th Army: Lieutenant General Luigi Nava had the mission to attack with IX Corps (Rome) and the I Corps (Turin) from Cadore between Cismontal (exclusive) and Mte. Peralba, silence the Sexten, Landro and Tre Sassi fortifications and to take into possession the area from Toblach as well as those heights surrounding the Sella Group.
Carnic Group: Lieutenant General Clemente Lequio with 16 Alpini and 3 customs battalions as well as 2 brigades of the XII Corps (Palermo) were in the area between Mte. Peralba and Mte. Maggiore to cover the advance of the 2nd and 3rd armies and commence the assault on the fortifications of Malborgeth, Raibl and Predil.
2nd Army: Lieutenant General Pietro Frugoni, had to assemble with the IV Corps (Genoa), II Corps (Alessandria) and the VI Corps (Bologna), plus a Bersaglieri division and 2 Alpini Groups in the sector between Mt. Maggiore and the Cormons-Görz (Gorizia) road and conduct the preparation for the awaited order from the high command to cross the Isonzo at Caporetto and if possible to take the Kolowrat ridge and the Korada.
3rd Army: Lieutenant General Vittorio, the Duke of Aosta, was assigned with the X Corps (Naples), XI Corps (Bari), VII Corps (Ancona) and with the army cavalry to the battle zone between the Cormons-Görz road and the sea. They had similar goals and requirements as the 2nd Army, to sieze the heights of Medea and the Isonzo bridges at Pieris.
General Cadorna had conflicting difficulties. He was not in a position to mount an offensive into Austrian territory until he had sufficient dependable troops to do so. He also had to plan for the possibility of a surprise Austro-Hungarian attack. To counter this threat he had the Carnic Group and the two right flank armies hold the line Mt. Peralba-Mt.Maggiore-Mt.Matajur-Cividale-Campoformido and thence Southwards towards the Adriatic.
As the strategic reserve the Italian high command planned to position the VIII Corps (Florence) and then the newly mobilised corps from the militia divisions - XIII and XIV to the area East of the River Etsch (Adige) to cover the valley exits of the Tridentina Front. They could later, if not required here be moved to the main theatre of operations.
As the Italian concentration was in full swing, General Cadorna issued the first operations orders on the 16th of May, the contents instructing the Carnic Group as well as the 2nd and 3rd armies to hold themselves ready on receipt of telegraphic orders for the attack against the Carinthian fortifications and against the Isonzo crossings. In this first phase, in which the 2nd Army should precede the 3rd, the possession of the Caporetto basin, Krn, Mrzli vrh, Kolowrat Ridge, Ježa, Korada then Mt.Quarin, Mt.Medea, the line Torrente Torre-Judrio and the lower reaches of the Isonzo were aspired to. Although it was Cadorna's wish that this action should have the character of an energetic surprise penetration, the first objectives were chosen remarkably closely; they lay without exception from Tolmein (Tolmino) downwards along the line of the Isonzo bank. Only if no strong resistance were to be found, did he plan immediately subsequent to the first phase to cross the Isonzo at which point the 2nd Army should again precede in the attack on the Bainsizza plateau, in order to facilitate the occupation of the Görz basin and the Comen Plateau by the following 3rd Army echeloned to its right rear. A landing with four old cruisers on the right flank of the army in the bight of Triest was also planned. Rumours of the Austrian mine blockade however deterred the Italians before its implementation. The 4th Army was newly assigned on the 16th of May the task of effecting a penetration into the Puster valley.
On the 22nd of May general mobilsation was ordered, which actually in practice was only significant in the provision of horses and in the mustering of means of transport. On the same day at midnight the Italian supreme command issued from Rome by telegraph the order for hostilities to open on the 24th of May. At this time the full striking power of the army had yet to be reached as nearly half the divisions and parts of the army supply columns where still en-route or actually still in their places of mobilisation. At the last moment changes were also carried out in the deployment of the army, in which the VI Corps of the 2nd Army was transferred to the 3rd, for which 2nd Army received in return the XII Corps (only two brigades strong). X Corps as well as the 3rd and 4th cavalry Divisions were deployed as a further army reserve.
It was extremely fortuitous for the the Central Powers that Italy had delayed entering the conflict until some three weeks after the battle at Gorlice-Tarnow, a delay which they fully exploited. Italy's entry into the war which had been the outcome of the London agreement was somewhat laggard. The Russians felt themselves not incorrectly to be at a disadvantage. Furthermore, Italy's new allies had their patience stretched further by the lack of any decisive gains on the new Italian front and indeed for the first weeks of the conflict only a series of inconclusive border skirmishes were to be conducted which nowhere had any influence on the overall war situation.
The Border Battles in the Tyrol in May and June 1915
The Operational Considerations and Measures of the Opposing Sides
The South Tyrolean mountain border advanced on both sides of the River Etsch like a wedge against the upper Italian plain and formed a favourable opening against the two railways leading to Venetia as the empire's border was in places just a days march distant from the plains. This threat expressed itself most sharply from the Lavarone Plateau (Vielgereut)-Lavarone (Lafraun) as this comparatively favourable assembly area was barely 100 km from Venice. General Cadorna had taken these dangers into account by the assembly of more than a third of his army against the Tyrol and the initial readying of strong army reserves in the area Verona-Vicenza-Bassano. Similarly, the Tyrolean defence command had to count on the possibility of an envelopment of the Tyrol by Italian forces. The most dangerous point was in the area of Toblach because here the Puster valley railroad ran only 12 km distant from the border.
By voluntary abandonment at the very start of the many salients contained along the course of the 450 km long border and through the redeployment of the defence to the line of the permanent fortresses and the long line of crests of the Fassaner Alps, the Austrian front was shortened by more than 100 km. So, it transpired as General Conrad had always envisioned, that through this shortened line of planned field fortifications a great fortress was created out of the Tyrol as a whole which on the Western border maintained a defensive posture yet in the South and East in parts also offered the possibility for offensive operations. The firm base of Trient was the core of the defence.
In view of the lay out of the ground and the corresponding possibilities of an enemy invasion, the Austrian command divided the South Tyrol into five defence Zones or Rayons. The troops of Rayon I had to block the sector in the high mountains between the Swiss border and the Ortler, especially the road over the Stilfser Joch. To the South the garrison of Rayon II guarded the border area including as far as the Presanella and the Tonale Pass. In Rayon III, later named "South Tyrol", the defenders had the mission to neutralise any advance through the numerous invasion routes that congregated against Trient between the Chiese and Suganer Valleys. Rayon IV contained the crests of the Fassaner Alps and Rayon V the Dolomite Mountains area up to the Carinthian border.
The backbone of the defence was formed from the garrisons of the fixed fortifications. These were men of the Landesschützen regiments, equipped and trained especially for mountain warfare. The gendarmerie and customs posts, whose strength had been reinforced by 20 or 30 of the locally residing members of the Landsturm were the front line until the border was adjusted. The March and Landsturm battalions within the brigades had in the main alpine born and bred personnel in their ranks; the men of IR.29 and IR.37 on the other hand originated from the Hungarian plain. The Standschützen battalions were only formed after the appeal of the 19th of May at the same time as the alert. With a great enthusiasm, the youngsters under 18 and men over 45 years of age streamed to the colours true to the tradition of their forefathers of 1809 in order to help in the defence of their native soil. However, except for their skill in shooting, these Standschützen had hardly any military training at all. On the 23rd of May the defence command Tyrol disposed of 27½ battalions, 39 Standschützen battalions, 8 Landesschützen detachments, 1½ squadrons and 22 mobile batteries with 75 guns. Consequently 110 rifles were available foe every kilometre of front. The non mobile artillery amounted to 540 tubes. As the sole body of troops suitable for offensive operations, the German Alpenkorps under the command of Generalleutnant Konrad Krafft von Delmensingen started moving to the Tyrol from the 25th May. In the main this specially equipped divisional strength formation was composed of personnel from the mountains of Bavaria.
On the 25th of May, the former commander of the 1st Army, General der Kavallerie Viktor Dankl assumed command of the Tyrolean defence command. As he was entrusted with the defence of the Tyrol on the 23rd of May in Teschen, GdK. Dankl immediately decided to conduct an offensive defence. For this the March, Landsturm and Standschützen battalions had to defend the prepared positions, while the German Alpenkorps currently en-route should be employed as a mobile shock formation at a suitable moment. With regard for the two likely lines of attack of the enemy, the Pustertal as a strategic and Trient as a political goal, the Alpenkorps was to be deployed into the area of Bruneck-Brixen-Bozen-Auer from where it could counter an Italian invasion either at Bruneck or at Trient within a day.
Initial Italian operations were however hesitant and systematic and favourable opportunities to strike advancing Italian forces separately were limited. And although General Dankl had considered an attack South from the Dolomite sector, this had to be abandoned when on the 28th of May an advance of 4 Italian groups in the areas Folgaria-Lavarone, Val Sugana, against the Fassa range and against the Puster Valley had developed dangerously. Dankl had therefore to manage being gradually constricted and losing freedom of action. He therefore already urgently considered a relief operation. As the enemy troops, who had succeeded from Cortina d'Ampezzo seemed to have ceased its advance, Dankl decided before he turned against the enemy troubling the Val Sugana and against the the fortifications of Folgaria-lavarone, that he would undertake an operation East from the Fassa Valley with the Alpenkorps. In this manner the defence line here should up to the line Rolle pass-Pellegrinosattel-Marmolata-town of Cherz be protected from fire at which point also the former front and the road Arabba-Pordoijoch forming the liaison between Rayons IV and V should be retaken. However, this new, considerably shorter and tactically more useful line was partially on Italian ground.
The German high command "OHL" however, issued to the Alpenkorps on the 4th of June 1915 the order that they were not until further orders to enter Italian territory and should German and Italian soldiers encounter each other on Austrian soil, the Italians should for the time being be made to appear as the aggressors. The reasons for these barely understandable measures lay in the fact that Germany was not as yet at war with Italy. AOK was obliged to approve the German order and stated as a further reason for this restriction that in the case of hostilities between Germany and Italy, Rumania would also be obliged to intervene on the allied side.
These restrictions placed the Tyrolean defence command in a very bitter predicament and GdK. Dankl understandably assumed that the German troops presumably were destined only to cover the Brenner line immediately to the South of Germany but not to fight in the defence of the South Tyrol. He requested that the k.u.k. XIV. Korps (Innsbruck) be made available for the replacement of the now only conditionally employable German Alpenkorps. The AOK was however, due to the situation in the Russian theatre of operations not yet in the position, to make additional troops available and therefore Dankl had for the time being to remain purely on the defensive.
On the Italian side, of the the two large armies facing the South Tyrol, the 1st under General Brusati with a strength of 6½ infantry divisions, 4 bersaglieri regiments, 16 Alpini and 4 customs battalions had a purely defensive assignment. The 5 infantry divisions, 6 Alpini, 3 bersaglieri and 1 custom battalion strong 4th army which was already drawn up against Toblach was on the 22nd May ordered immediately after the declaration of war by the Italian high command to take strategically important points situated on the other side of the border into its hands for the forthcoming attack. The commander of the I Corps however struggled against a crossing of the border and the IX Corps only managed the seizure of the Saint Pellegrino pass and the crossings East of Valazza, both of which were situated in front of the Austrian defence line. The Italian Army commander feared apparently that through the capture of forward positions, the surprise factor against the enemy would be rendered impossible for further offensive action; he also thought that he had too weak a force to execute the assigned mission and in this way he threw away the opportunity to pierce the still weakly constructed Dolomite front at this particularly favorable moment in time.
Although the two Italian left flank armies on the first days of the war had a superiority of 190,000 rifles to the 50,000 defending the Tyrol, both sides limited themselves initially to only minor fighting. The Italian high command deduced from this that the Austrians were not yet capable or willing to offer serious resistance. As a similar situation was occurring on the Adriatic coastland, all army commanders were required to undertake decisive operations that would affect the character of the fighting and rapidly take the enemy positions that would not be seriously defended by the Austrians. General Cadorna's instructions closed with the exhortation to: "Enthusiasm, offensive spirit and the winning of moral superiority over the enemy." But as the right flank of the Italian army in front of the Austrian Isonzo front were to pay very dearly, this order was, as explained in the Italian General Staff history only applicable to the 1st and 4th Armies. With the first-mentioned which anyhow was already in several sectors preparing to move, the troops were now spurred on to quickly take those points, which were ordered to be permanently held.
The Events on the Tyrolean West Front and in Rayon "South Tyrol"
The very unfavourable snow conditions at the end of May were manifestly the reason that the five Alpini battalions including three mountain batteries, that had been deployed to the Stilfser Joch and the Tonale Pass at first received the order, to limit themselves to the occupation of a line, which ran 3 or 4 kilometres west of the perpetually snow and ice covered mountain border of the Ortler Massif. Advance troops were to occupy Mount Scorluzzo which dominated the road over the Stilfser Joch which was only snow free in July and August and to block some footpaths through gaps in the border. In the Tonale area, the occupation of the glacier free sections North and South of the pass running to the border had been ordered. An infantry regiment in Tirano was deployed in support.
On the Austrian side, the 53. Half-Brigade had to guard Rayon I with the exception of the Suldenbach Valley and also the Münster Valley because it was not yet clear whether the Italians would take into account Swiss neutrality. The old fort of Nauders protected the entry route to the Inn Valley. It also had to be ensured that projectiles fired against the Italians did not encroach onto Swiss territory. For these reasons and because of the still heavy snow situation, the initial grouping of the garrison left unguarded the border with Italy on the line Taufers - Schafberg - Sperre Gomagi - Innersulden - Firkelescharte.
In such a way, there was no fighting in the Ortler sector in May 1915. On the 4th June, however an Austrian Gendarmerie detachment seized by a daring advance the already held Mount Scorluzzo in Italian territory and in this manner secured the Stilfser Joch. As moreover, Swiss troops guarded their border, an Italian outflanking manouvre was not be feared, the defensive front was indeed gradually and without enemy counteraction in the forward edge of the battle area advanced to the much higher lying line: Stilfser Joch - Mount Scorluzzo - Naglerspitze, which was held until the war's end.
To be continued.....