The fleet had undertaken only three major sorties at full strength into the North Sea since June 1916: 18–19 August 1916, 18-19 October 1916, and 22–25 April 1918. This prolonged period of relative inactivity, at a time when all other branches of Germany's armed forces were very heavily engaged, did much to undermine the morale of the crews and the self-respect of the officers. Acts tantamount to mutiny took place on various occasions during 1917, the most noteworthy being the arrest of 200 men from the battleship Prinzregent Luitpold in August, resulting in two executions.