autocrat (n.)

1800, used in reference to the Russian tsars, then to Napoleon, from French autocrate, from Latinized form of Greek autokrates "ruling by oneself, absolute, autocratic," from autos "self" (see auto-) + kratia "rule," from kratos "strength, power" (see -cracy). The Greek noun was autokrator, and an earlier form in English was autocrator (1759). Earliest forms in English were the fem. autocratress (1762), autocratrix (1762), autocratrice (1767, from French).