Karl Křitek was born on the 24th of October 1861 in Spalato (Dalmatia) as the the son of a senior military intendance official (Generalintendant). He attended the academic junior gymnasium in Vienna followed by the first year at the military college at St. Pölten and finally the famous military school at Mährisch-Weißenkirchen which had already provided many reputable military leaders in the past. From 1876 until 1879 Křitek attended the Theresia military academy at Wiener-Neustadt with which he left "with great success" and was commissioned as a Leutnant on the 18th August 1879 in infantry regiment number 52. From 1882 until 1884 he attended the war school in Vienna and on successful completion of the course was attached to the general staff as an Oberleutnant. His initial staff posting was with the 40th infantry brigade followed by an assignment to the13th infantry division at Banja Luka. After his promotion to Hauptmann in the general staff he served on the staff of the 12th corps at Nagyszeben until 1891 and was then transferred for the first time to the department in the general staff that dealt with the mapping of foreign countries. Following a short field assignment with infantry regiment number 49 he was posted as the chief of staff to the 8th infantry division at Innsbruck in the rank of Major. After a further tour at regimental duty with infantry regiment 85 he was promoted to Oberst in 1900 and became head of the aforementioned mapping bureau within the general staff. Under his leadership the department was organized into sections dealing with the possible theatres of war and for the first time provided with it's own archives.
Promoted to Generalmajor on the 1st of November 1906 Křitek commanded first the 20th infantry brigade at Königgrätz and then the 49th infantry division in Vienna. Promoted to Feldmarschall-Leutnant on the 1st of November 1910 at the outbreak of the First World War he at first commanded the 26th Landwehr infantry division and took part with this command in the offensive against Zamocz-Komarów. He was then entrusted with the command of the newly formed 17th corps and on the 17th of October 1914 promoted to General der Infanterie. Within the framework of the 4th army, 17th corps formed the North flank and held their ground against the Russian counter-attack during the battle of Limanowa. Following a reorganization Křitek's corps took part under command of 3rd army in the winter battles in the Carpathian mountains where the 17th corps suffered very heavy losses in the battles around the Dukla Pass. Following the breakthrough at the battle of Gorlice-Tarnów Křitek's corps returned to 4th army and participated in the victorious fighting at Krasnik and Lublin. Despite his success, on account of his somewhat bureaucratic and pedantic character he was not particularly loved by either his superiors or his subordinates. General Boroević wrote in an efficiency report "Not suitable for higher command.." !
In the Autumn battles on the Styr, Křitek and his corps played an important role and in 1916 were finally transferred to the South Tyrol and placed under the command of Generaloberst Hermann Kövess's 11th army for the Trentino offensive against Italy. According to the plan, Křitek was attack in the Val Sugana in the direction of Bordo and to capture said place by the 22nd of May. Although assault detachments of his 17th corps successfully attacked in the sector of the 3rd corps he was unable to make the decisive breakthrough to the plains. In the Autumn of 1916 he was again placed under the command of Generaloberst Boroević and took part in the 6th and 9th battles of the Isonzo. Boroević had cause to revise his opinion of the General; "An especially efficient, energetic general, undoubtedly suitable for the leadership of the next highest command..."! After FM Conrad had also endorsed this judgment Křitek at first received the command of the 10th corps on the Eastern front.
On the 1st of May 1917 he was promoted to Generaloberst and received as the successor to Generaloberst Tersztyánszky the command of the 3rd army. Following the successful breakthrough at Zborow in cooperation with the German Südarmee, he succeeded in driving the Russian troops back and liberating the Bukowina. In January 1918 assumed command of then united 3rd and 7th armies and took part in the advance into the Ukraine. Here despite continuous small skirmishes and engagements on account of troop transfers and organizational restructuring, Generaloberst Křitek's leadership career found its end. On the 15th of April 1918 the 7th army headquarters was dissolved and Křitek placed "at disposal".
A new appointment as an army commander was out of the question as all the senior commands were already filled. The duty conscious and modest general - who had already turned down a title of nobility retired completely from public life after the collapse of the monarchy. He died on the 3rd of September 1928 in Vienna.