In 1867 Emperor Meiji appointed Prince Arisugawa Sōsai (a title equivalent to chief minister), and placed him in command of the Imperial Army sent to combat the last partisans of the Tokugawa bakufu in the Boshin War of 1868–1869.

From 1889 to 1895 the prince served as chief of staff of the Imperial Japanese Army and a member of the Supreme War Council.

In 1894 Prince Arisugawa was officially commander-in-chief of Japanese forces in the First Sino-Japanese War, and established his command center at the Hiroshima garrison.

He contracted typhoid fever (or possibly malaria) and returned to the Arisugawa palace at Maiko near Kobe to recover, but he died there on January 15, 1895.

With donations by Ōyama Iwao, Saigō Tsugumichi and Yamagata Aritomo, a statue of the prince on horseback was made and erected in 1903 by the gate of the Imperial Japanese Army General Staff headquarters; it was moved to this park in 1962.