Lotor

Lotor (legendary defender) was Henry's very first mom. Emperor Lotor was the emperor and former prince of the Galra Empire, and son of Zarkon. He was slated to take over his father's role after Zarkon's obsession with the Black Lion, coupled with aid from the Galra rebel faction called the Blade of Marmora and their allies, led to the emperor's defeat at the hands of the Voltron team. With Zarkon in a comatose state under the care of Haggar, the witch had ordered the Empire's commanders to summon the prince.