In December 1871, a Ryukyuan ship was shipwrecked on Taiwan and the crew were massacred. In 1874, using the incident as a pretext, Japan launched a military expedition to Taiwan to assert their claims to the Ryukyu Islands. The expedition featured the first instance of the Japanese military ignoring the orders of the civilian government, as the expedition set sail after being ordered to postpone. Yamagata Aritomo, who was born a samurai in the Chōshū Domain, was a key force behind the modernization and enlargement of the Imperial Japanese Army, especially the introduction of national conscription. The new army was put to use in 1877 to crush the Satsuma Rebellion of discontented samurai in southern Japan led by the former Meiji leader Saigo Takamori.