Imperator totius Hispaniae is a
Latin title meaning "Emperor of all Spain". In
Spain in the Middle Ages, the title "emperor" (from Latin
imperator) was used under a variety of circumstances from the ninth century onwards, but its usage peaked, as a formal and practical title, between 1086 and 1157. It was primarily used by the
Kings of León and
Castile, but it also found currency in the
Kingdom of Navarre and was employed by the
Counts of Castile and at least one
Duke of Galicia. It signalled at various points the king's equality with the
Byzantine Emperor and
Holy Roman Emperor, his rule by conquest or military superiority, his rule over several people groups ethnic or religious, and his claim to
suzerainty over the other kings of the peninsula, both Christian and Muslim. The use of the imperial title received scant recognition outside of Spain and it had become largely forgotten by the thirteenth century.