 Alfonso VI's penultimate marriage was to Isabel and "the cause of controversy during centuries has been whether this Isabel was the same person as Zaida or a different individual".Both appear together for the first time on 14 May 1100 although the diploma is considered suspicious, and the second time in that same year at an unspecified date.Isabel's last mention in royal diplomas was on 8 and 14 May 1107 and she probably died in the middle of that year.