The Funj Sultanate, also known as Funjistan, Sultanate of Sennar or Blue Sultanate, was a monarchy in what is now Sudan, northwestern Eritrea and western Ethiopia. Founded in 1504 by the Funj people, it quickly converted to Islam, although this conversion was only nominal. Until a more orthodox form of Islam took hold in the 18th century, the state remained an "African empire with a Muslim façade", coming to rule over an ethnically diverse population.