autocracy (n.)

1650s, "independent power, self-sustained power, self-government" (obsolete), from French autocratie, from Latinized form of Greek autokrateia "absolute rule, rule by oneself," abstract noun from autokrates "ruling by oneself," from autos "self" (see auto-) + kratia "rule" (see -cracy). Meaning "absolute government, unlimited political power invested in a single person" is recorded from 1855.