the.com/lord protector

means A head of state who rules with monarch-level power but a republican-sounding title, usually installed after a crown has been forcibly vacated.

from The title rose to fame with Oliver Cromwell, who took it in England in 1653 after the monarchy had been abolished and the king executed. 'Protector' had already been used for regents who governed on behalf of child monarchs — guarding the throne rather than sitting on it. Cromwell's innovation was keeping that humble, guardian-sounding word while quietly wielding full royal authority himself, crown or no crown.