Updated

Among those caught in the unprecedented arrests this week of top princes, wealthy businessmen and senior officials was the scion of one of Saudi Arabia's most recognizable families: Bakr Binladin, the chairman of the kingdom's pre-eminent contractor — and Osama bin Laden's half-brother.

It was a stunning end to a decades-old alliance between the ruling Al Saud and Binladin families that saw the Saudi Binladin Group secure a near-monopoly on mega-expansion projects in Islam's two holiest sites, Mecca and Medina, throughout the reigns of successive Saudi monarchs.

It also speaks to the larger demands on the business community to pay into the crown prince's economic vision in an era of lower oil prices.