 A papal letter written 28 June 1077 could not have been received by Alfonso more than twelve weeks before the date of the first known usage of the title "emperor" by him.This letter was addressed to the "kings, counts, and other princes of Spain" ("regibus, comitibus, ceterisque principibus Hyspaniae"), an indication that Gregory did not regard Alfonso as unique among Spanish rulers.The term "Kingdom of Spain" was employed in this letter to refer to the Christian part of the peninsula and not to Alfonso's kingdom in particular, since the legates Gregory said he was sending there never even entered the latter.