Between 1769 and 1855, Ethiopia experienced a period of isolation referred to as the ''Zemene Mesafint'' or "Age of Princes". The Emperors became figureheads, controlled by regional lords and noblemen like ''Ras'' Mikael Sehul of Tigray, ''Ras'' Wolde Selassie of Tigray, and by the Yejju Oromo dynasty of the Wara Sheh, such as ''Ras'' Gugsa of Yejju. Prior to the Zemene Mesafint, King Iyoas had introduced the Oromo language (''Afaan Oromo'') at court, instead of Amharic.