What is "dai-gensui"

Dai-gensui was the highest rank of the Greater Imperial Japanese Army and the Imperial Japanese Navy from the 1870s to 1945, when the Empire of Japan was dissolved. Only ever held by the Emperor of Japan as commander-in-chief of the Empire, the rank was equivalent to a generalissimo or general of the armies (a six-star rank), and senior to the rank of gensui ("marshal"). It formally became obsolete in 1947 when the Imperial Japanese armed forces were abolished.