Abu-l-Qasim Ahmad ibn al-Husayn ibn Qasi
Abūʾl-Qāsim Aḥmad ibn al-Ḥusayn ibn Qasī was a Sufi, a rebel leader against the Almoravid dynasty in Al-Garb Al-Andalus and governor of Silves for the Almohads. The main sources for his life are Ibn al-Abbār, Ibn al-Khaṭīb and ʿAbd al-Wāḥid al-Marrakūshī. The last is the source for his biography in the biographical dictionary of al-Ṣafadī.
He was of native Iberian stock, rūmī al-aṣl in the words of Ibn al-Abbār. He was born at Silves, but the date of his birth is unknown. His name sustains the possibility that he was a descendant of the Banu Qasi, that had once staged a rebellion against the Emirate of Cordoba. According to Ibn al-Abbār, he was a minor government official at Silves, while Ibn al-Khaṭīb describes him as a spendthrift. He eventually sold all his goods, gave the money to the poor and became a murīd. He studied under Khalaf Allāh al-Andalusī and Ibn Khalīl in Niebla, although he may also have met Ibn al-ʿArīf in Almería. His main influences were the Encyclopedia of the Brethren of Purity and the works of al-Ghazālī.
Ibn Qasī wrote a treatise "the Removal of the Sandals", this book revolves around Ibn Qasi's Philosophy, Sufism and History. Ibn Arabi has written a commentary on some parts of this treatise.
He was also an ally and friend of Afonso Henriques, first king of Portugal, and this association eventually led to his assassination at Silves in 1151.