Al-Wathiq, Abbasid caliph (d. 847)
Abū Jaʿfar Hārūn ibn Muḥammad (Arabic: أبو جعفر هارون بن محمد المعتصم; 18 April 812 – 10 August 847), better known by his regnal name al-Wāthiq bi’llāh (Arabic: الواثق بالله, lit. 'He who trusts in God'), was an Abbasid caliph who reigned from 842 until 847 AD (227–232 AH in the Islamic calendar). The chief events of his reign were the suppression of a Bedouin rebellion in the Hejaz in 845 and an abortive uprising in Baghdad in 846. The conflict with the Byzantine Empire continued, and the Abbasids even scored a significant victory at Mauropotamos, but after a truce in 845, warfare ceased for several years.