sentences:  Abu Bakr began the construction of Marrakech in May 1070.Work had not progressed very far when a messager arrived pleading for his help in suppressing a revolt against the Almoravids deep in the Sahara Desert.Abu Bakr knew that his wife was not suited to the rigours of a desert life, and divorced Zaynab, advising her to marry Yusuf ibn Tashfin, whom he was leaving as his deputy.