From Wikipedia, just in case you didn't want to know. But there were many other defenestrations throughout Europe. Seems that throwing your opponents out of a high window was quite common.

In 1378 the crafts and their leader Wouter van der Leyden occupied the Leuven city hall. They took over the Leuven government. Most of the patricians left the city and fled to Aarschot. After negotiations between the parties, they agreed to share the government. The patricians did not accept this easily, as they lost their absolute power. Trying to turn the tide, they had Wouter van der Leyden assassinated in Brussels. The crafts wanted revenge. They handed over the patrician to a furious crowd. The crowd stormed the city hall and threw the patricians out of the window. At least 15 patricians were killed during this defenestration of Leuven.