Yusuf ibn Tashfin or Tashufin was the Berber Almoravid ruler in North Africa and Al-Andalus (Moorish Iberia). He took the title of "amir al-muslimin" ("commander of the Muslims"). He was either a cousin or nephew of Abu Bakr ibn Umar, the founder of the Almoravid dynasty, and married Zaynab an-Nafzawiyyat, a former wife of Abu Bakr. Wikipedia
The definitive Wikipedia entry for Yusuf Ibn Tashfin. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Yusuf_ibn_Tashfin
