Abu Bakr Muhammad ibn al-Walid al-Tartushi, Abu Bakr Al-Tortuchi (أبو بكر محمد بن الوليد الطرطوش) (451 AH - 520 AH) (1059 – 1127 AD/CE) was a famous Muslim jurist from Tortosa, in the northern region of Al-Andalus at the delta of the river Ebro.
He travelled for knowledge, seeking to educate himself on various scholars in different part of the world and went as far east as Baghdad. On his way he also stopped at Damascus, Aleppo, Cairo, and Alexandria.
In Alexandria, Egypt, he taught at a school. He strongly opposed the Ismaili ideology of the Fatimid dynasty in Egypt. He also issued a fatwa for Yusuf Ibn Tashfin, the Almoravid ruler of Al-Andulus (Muslim Spain). This allowed him to invade Spain and depose of the divided Taifa kingdoms.
His most famous work was Siraj al-Muluk (سراج الملوك).