Belgium has a tradition of religious gentlemen known as monks. And these monks have a reputation for making some mighty fine beer (and cheese).
The abbey was founded in 1121 and the beer 100 years later. During the French Revolution the monks skipped town, or the abbey but in 1960 the beer was rediscovered.
Actually the beer is no longer brewed there but still keeps the Floreffe name. It is now made by a brewery in Mechelen, about an hour or so north.