Tripel was the strongest beer in their range, in 1956, served at a Trappist brewery in what country?
Tripel:  It was used in 1956 by the Trappist brewery, Westmalle, to rename the strongest beer in their range, though both the term Tripel and the style of beer associated with the name (strong pale ale), were in existence before 1956. Westmalle Brewery: Westmalle Brewery (Brouwerij der Trappisten van Westmalle) is a Trappist brewery in the Westmalle Abbey, Belgium.
Belgium