Although the Ibn Touloun Mosque is the oldest intact example of Islamic architecture in Egypt (879), it is not the first built: Amr ibn al-As Mosque was founded in 642, but has only retained a few elements from its original construction (to the south of the eastern iwan). The building was extended in the 9C to meet the needs of a growing population, and then reworked in the 15C and again in 1983.