The Abbasid Caliphate, with its capital in Baghdad, oversaw the 'Islamic Golden Age.' During this time, Baghdad became the world's center for science, philosophy, medicine, and education. A central feature was the 'House of Wisdom' (Bayt al-Hikma), where scholars translated Greek, Persian, and Indian texts into Arabic. Scholars like Al-Khwarizmi (the father of Algebra) and Ibn Sina (Avicenna) made breakthroughs that preserved classical knowledge and advanced mathematics and medicine by centuries. This era of intellectual flourishing was eventually brought to a brutal end by the Mongol Siege of Baghdad in 1258, but the knowledge preserved here laid the essential groundwork for the European Renaissance.