Mahmoud Shakir, who is Sheikh Abu Usama Mahmoud bin Shakir Shakir al-Harstani, is a Syrian historian and Islamic writer. He was born in Harasta, northeast of Damascus in the month of Ramadan in 1351 AH / 1932 AD, and died in Riyadh on the first Sunday of Safar al-Khair in 1436 AH corresponding to November 23, 2014. He studied elementary, middle and high school, and graduated from them in 1371 and 1952. He received forensic sciences at the hands of some scholars in the mosques of his town. Then he joined the University of Damascus to study geography, then graduated from it in 1956-1957. After that, he joined the mandatory military service, and graduated as a lieutenant, then was assigned to the front as an artillery officer on the border with Palestine in the northern sector in 1960 AD. Then he returned to teaching. He was passionate about studying the science of history with its arts, and he promoted Islamic history and became prominent in it, and classified it in an innovative way, and he was distinguished for accurately formulating his history in its past and present from the Islamic point of view with the presentation and analysis of events, and he responded in his writings to some of the suspicions raised by orientalists and their followers. He was interested in studying genealogy, and excelled in it. He moved to Saudi Arabia in 1972 and worked as a professor of geography and Islamic history at the College of Social Sciences in Riyadh and Qassim. He had prepared a radio program on Quran Radio from Saudi Arabia called The Geography of the Islamic World. He has more than two hundred works on history, Islamic thought and geography. He also participated in the development of curricula and study plans in the sciences of history and geography. He passed away on the first day of Safar, Sunday, 1436 AH / corresponding to November 23, 2014 AD