The third holiest sight in Islam? In point of fact this was an ignored old mosque for most of the last several centuries. Nobody paid any attention to it and it was not considered of any particular significance.  In fact, Jerusalem itself was never considered a holy city by Muslims. It's not mentioned in the Koran or hadiths. It was largely ignored during its long centuries of Muslim rule as a backwater town of no importance. It only became 'holy' as Muslims confronted Jews, and has been built up to be this grand and gloriously important city with exaggerated importance for mosques like Al Aqsa out of sheer political expediency. BTW, a bit of irony: Jordan's king was assassinated in this mosque by a Palestinian back in 1951.