 Political conflicts in Vienna delayed Austria 's entry into the Third Coalition until 1805 . After hostilities of the War of the Second Coalition ended in 1801 , Archduke <unk> emperor 's <unk> advantage of the subsequent years of peace to develop a military restructuring plan . He carefully put this plan into effect beginning in 1803 – 04 , but implementation was incomplete in 1805 when Karl Mack , Lieutenant Field Marshal and Quartermaster @-@ General of the Army , implemented his own restructuring . Mack bypassed Charles ' methodical approach . Occurring in the field , Mack 's plan also undermined the overall command and organizational structure . Regardless , Mack sent an enthusiastic report to Vienna on the military 's readiness . Furthermore , after misreading Napoleon 's maneuvers in Württemberg , Mack also reported to Vienna on the weakness of French dispositions . His reports convinced the war party advising the emperor , Francis II , to enter the conflict against France , despite Charles ' own advice to the contrary . Responding to the report and rampant anti @-@ French fever in Vienna , Francis dismissed Charles from his post as generalissimo and appointed his <unk> brother @-@ in @-@ law , Archduke Ferdinand , as commander . 
