Federal Fortress of Mainz 20 July 1866
With the approaching hostilities in the summer of 1866, the federal fortress of Mainz, initially garrisoned predominantly by Austrian and Bavarian troops was declared neutral and a Bavarian governor appointed. With the actual outbreak of hostilities the remaining Prussian elements of the fortress staff and garrison withdrew and the situation regarding the order of battle of the fortress on the 20th of July 1866 is reflected below. Although subjected to some shelling and encirclement the fortress of Mainz did not become a major battlefield and was eventually handed over to the Prussians on the 26th of August 1866. It can be seen that the garrison was indeed a federal affair with various contingents. The Austrian contingent amounted to 15 officers, 14 military officials, 39 non commissioned officers, 1 drummer and 121 private soldiers for a total of 190 personnel. The entire garrison, which included 7 general officers totaled 16,408.
| Government | |
| Governor | Kgl. Bayer. Generalmajor Ludwig Graf von Rechberg und Rothenlöwen |
| Attached Staff: | Kgl. Bayer. Oberst Nepomuk Freiherr von Müller |
| Kgl. Bayer. Major Kleeman | |
| Kgl. Bayer. Hauptmann Gustav Waagen | |
| Kurf. Hessischer Oberleutnant von Bardeleben | |
| Kgl. Bayer. Kriegskommissär Peter Bauer | |
| Kgl. Bayer. Regiments-Auditor Christoph Fischbacher | |
| Kgl. Bayer. Sekretär Joseph Wengner | |
| Fortress Command | - |
| Commandant | Herzogl. Sachsen-Meiningenscher Oberst Gustav von |
| Adjutants: | Herzogl. Sachsen-Meiningenscher Oberleutnant von Buch |
| Kgl. Bayer. Oberleutnant Ludwig Schönhammer | |
| - | |
| Station Headquarters | |
| Station Commander | K.k. Oberstleutnant Maximilian Graf Berghe von Trips |
| Adjutants: | K.k. Hauptmann Anton Vest |
| Kgl. Bayer. Oberleutnant Karl Gundermann | |
| - | |
| K.k. Miltary Command | |
| Commandant | K.k. Oberst Karl Pirner |
| - | |
| Artillery Director | K.k. Oberst Karl Hofmann von Donnersberg |
| - | |
| Engineer Director | Kgl. Bayer. Major Gottlieb Kollmann |
| - | |
| Field Hospital | |
| Director | K.k. Oberstabsarzt Dr. Oswald Bleyle |
| Commandant | K.k. Oberleutnant Julius Egloff |
| - | |
| Supply Commissioner | K.k. Kommissär Karl Stichenwirth |
| - | |
| Fortress Paymaster | K.k. Kriegskassier Eduard Przihoda |
| - | |
| Garrison Chaplain (Catholic) | K.k. geistlicher Rat Johann Nepomuk Cori |
|
Units |
|
| Generals and General Staff: | Kurf. Hessischer Generalmajor Karl von Loßberg |
| Kurf. Hessischer Genealmajor Ludwig Freiherr Treusch von Buttlar-Brandenfels | |
| Kurf. Hessischer Generalmajor Friedrich von Specht | |
| Kurf. Hessischer Generalmajor Ernst Coch von Cochenhausen | |
| Kurf. Hessischer Generalmajor Albrecht von Bardeleben | |
| Electoral Hessian Chief of Staff | Kurf. Hessischer Major Darapsky |
| Herzogl. Nassauischer Generalmajor Peter von Hollbach | |
| - | |
| Infantry | |
| Kgl.Bayer. Infanterie-Leib-Regiment 1. Bataillon | Major Franz Exkart |
| Kgl.Bayer. 1. Infanterie-Regiment 1. Bataillon | Major Franz Dassenreither |
| Kgl. Württ. 4. Infanterie-Regiment 1. & 2. Batallion | Oberst von Burkhardt |
| Kurf. Hessisches Leib-Garde-Regiment 1. & 2. Batallion | Oberst Karl Freiherr Schenck zu Schweinsberg |
| Kurf. Hessisches 1. Infanterie-Regiment 1. & 2. Batallion | Oberstleutnant von Bischoffshausen |
| Kurf. Hessisches 2. Infanterie-Regiment 1. & 2. Batallion | Oberst von Osterhausen |
| Kurf. Hessisches 3. Infanterie-Regiment 1. & 2. Batallion | Oberst von Heimrod |
| Kurf. Hessisches Schützen-Batallion | Major von Oeynhausen |
| Kurf. Hessisches Jäger-Batallion | Major Hofmann |
| Herzogl. Sachsen-Meiningensches Füsilier-Regiment 1. & 2. Batallion | Oberst von Buch |
| Herzogl. Nassauisches Depot-Bataillon | Oberstleutnant Chelius |
| Kgl. Hannoversches Legion | Hauptmann von Düring |
| - | |
| Cavalry | |
| Kurf. Hessisches Garde du Corps | Major von Eschwege |
| Kurf. Hessisches 1. Leib-Husaren-Regiment | Oberst von Baumbach |
| Kurf. Hessisches 2. Husaren-Regiment | |
| - | |
| Artillery | |
| Kgl. Bayer. 2. Artillerie-Regiment 2. Fußbatterie | Hauptmann Maximilian Freiherr von Branca |
| Kgl. Bayer. 4. Artillerie-Regiment 2. Fußbatterie | Hauptmann Matthäus Schmautz |
| Kgl. Bayer. 4. Artillerie-Regiment 4. Fußbatterie | Hauptmann Oskar Neu |
| Kgl. Württ. Festungs-Artillerie | Hauptmann Cuhorst |
| Kurf. Hessisches Artillerie 3 Fußbatterien & 1 reit. Batterie | Generalmajor von Cochenhausen |
| Großh. Badische Abteilung | Oberleutnant Holtz |
| Großh. Hessische Abteilung | Leutnant Schenk |
| Herzogl. Nassauisches Depot | Hauptmann Menche |
| - | |
| Engineers | |
| K.k. 1. Genie-Regiment ½ Kompagnie | |
| Kgl. Bayer. Genie-Regiment 5. Festungs-Genie-Kompagnie | Hauptmann Lorenz Bauer |
| Kurf. Hessische Pionier-Kompagnie | Hauptmann Staehle |
Notes:
| Kgl. Bayer | Royal Bavarian |
| K.k. | Imperial-Royal (Austrian) |
| Kurf. Hessische | Electoral Hessian |
| Kgl. Württ. | Royal Württemberg |
| Großh. Badische | Grand Ducal Baden |
| Großh. Hessische | Grand Ducal Hessian |
| Herzogl. Nassauische | Ducal Nassau |
| Herzogl. Sachsen-Meiningensche | Ducal Saxon-Meiningen |
| Kgl. Hannoversche | Royal Hanoverian |