The Abbadid dynasty or Abbadids (Banū ʿAbbād) was an Egyptian Arab Muslim dynasty which arose in al-Andalus on the downfall of the Caliphate of Cordoba (756–1031). After the collapse, they were the strongest Taifa and before long absorbed most of the others. Abbadid rule lasted from about 1023 until 1091, but during the short period of its existence it exhibited singular energy and typified its time. During their reign, the Abbadids also made significant contributions to the development of science and medicine. Their patronage of scholars and researchers helped to create a culture of learning that encouraged scientific inquiry and experimentation. The Abbadids' interest in science is evident in the many scientific works that were written during their reign, including the famous Book of Optics by the polymath Ibn al-Haytham. In addition to their patronage of the arts, sciences, and literature, the Abbadids also made significant contributions to the development of Islamic law and jurisprudence. They were known for their fair and just rule, and they encouraged the use of Islamic law to settle disputes and conflicts. This helped to create a stable and peaceful society in Andalusia, which was admired by people throughout the Muslim world. Despite their many achievements, the Abbadids were eventually overthrown by the Almoravids, who were more conservative and orthodox in their interpretation of Islam. The Almoravids saw the Abbadids' tolerance of other religions and cultures as a threat to the purity of Islam, and they were determined to impose their own strict interpretation of the faith on Andalusia. This led to a period of religious and cultural repression that stifled the creative and intellectual energy of the region. Despite their eventual downfall, the Abbadids left a lasting legacy in Andalusia. They were known for their love of art and architecture, their patronage of literature and science, and their tolerance of other religions and cultures.