Shajar al-Durr (Arabic: شجر الدر, lit. 'Tree of Pearls'), also Shajarat al-Durr (شجرة الدر),[a] whose royal name was al-Malika ʿAṣmat ad-Dīn ʾUmm-Khalīl Shajar ad-Durr (الملكة عصمة الدين أم خليل شجر الدر;[b] died 28 April 1257), was a ruler of Egypt. She was the wife of As-Salih Ayyub, and later of Izz al-Din Aybak, the first sultan of the Mamluk Bahri dynasty. Prior to becoming Ayyub's wife, she was a child slave and Ayyub's concubine.[4] In political affairs, Shajar al-Durr played a crucial role after the death of her first husband during the Seventh Crusade against Egypt (1249–1250 AD). She became the sultana of Egypt on 2 May 1250, marking the end of the Ayyubid reign and the start of the Mamluk era.[5][6][7][8]