It is no happy accident that the Dome of the Rock and Al Aqsa Mosque were built where they were. The year was 688AD. Islam was in its infancy, having been founded just 66 years earlier. 
Muhammed had failed in his attempts to convince the Jews of Medina (or elsewhere for that matter) that Islam was the way forward, and that they should convert.
On his death in 632AD, the Rashidun Caliphate began, with Muslim armies (at times numbering over 100,000 strong) rampaging across Asia, North Africa and the Middle East.
The siege of Jerusalem itself began in 636, with its final conquest and occupation in 638. Fifty years on, the Umayyad Caliph Abd Al Malik wanted to complete the ‘Islamification’ of this Jewish City.
The site intentionally chosen was the Temple Mount, the most sacred of places to all Jews. Al Malik was attempting to make a statement to both Jews and Christians - that Islam was righteous, all powerful and would supersede both religions.
This intentional occupation of sacred Jewish land was totally disrespectful, the ultimate insult, and remains so to this day
