Emperor of the Two Religions

He directly ruled over the Christian kingdoms of León and Castile, including the ancient Visigothic capital of Toledo, and also extracted tribute (parias) from the petty Muslim rulers of al-Andalus.

[3] Two actual letters of Alfonso containing variants of the title were copied into the anonymous 14th-century Arabic chronicle Al-Ḥulal al-mawshīya, which was written by a Spanish Muslim.

[c] Álvar is known to have rejoined Alfonso's court only in February 1085 after spending time in voluntary exile with Rodrigo Díaz de Vivar (El Cid).

[3] The Ḥulal, which is a strongly pro-Almoravid text, portrays al-Muʿtamid's subsequent request to the Almoravids for assist as a direct response to Alfonso's new demands and titles.

[6] The authenticity of the letters was accepted by Ramón Menéndez Pidal, Luis García de Valdeavellano and the Egyptian scholar Muḥammad ʿAbd Allāh ʿInān.

[1] Hélène Sirantoine suggests that the Arabic sources are in effect translating this title so as to indicate clearly Alfonso's claim to rule over Muslims, which was unacceptable to them.

[2] A Latin title similar to "Emperor of the Two Religions" is, however, found in the dating clauses of a pair of private charters from Sahagún dated to 1098 and 1104: regnante rex domno Adefonso in Toleto et imperante christianorum quam et paganorum omnia Hispanie regna ("the lord king Alfonso reigning in Toledo and commanding all the kingdoms of Spain both of the Christians and of the pagans").