The Al Aqsa Mosque in Jerusalem was originally built by the fifth Umayyad caliph Abd al-Malik (685–705) or his successor al-Walid I (705–715) (or both) as a congregational mosque on the same axis as the Dome of the Rock, a commemorative Islamic monument. Muslims regard the site as the third holiest in Islam, after Mecca and Medina.
On 21 August 1969, a fire was started by a visitor from Australia named Denis Michael Rohan, who initially set fire to the pulpit. The 12th-century minbar of the al-Aqsa Mosque was destroyed in the fire.
Rohan had hoped that by burning down al-Aqsa Mosque he would hasten the Second Coming of Jesus. Initially, Israelis blamed the fire either on an accident related to ongoing renovations, or to a false flag attack by Palestinian group Fatah.
Israel subsequently arrested, tried and sentenced Rohan to a mental institution after it was determined he had a history of mental illness. Eventually he was repatriated to Australia and sent to a mental institution.
The fire at Al-Aqsa was the cause of great anger in the Muslim world, and demonstrations and riots occurred. Muslims blamed Israel for this event. The event has been described as "an act which plunged the Middle East into its worst crisis since the June, 1967, Arab-Israel War", and was a key catalyst for the creation of the Organisation of Islamic Cooperation.
Source: Wikipedia