During World War I a historical event took place in Belgium on Christmas Eve, 1914 - which?

Explanation

During World War I an unofficial Christmas truce took place. The truce began December 24, 1914. German troops began decorating the area around their trenches in Belgium for Christmas. Then placing candles on trees, singing Stille Nacht. The British troops responded by singing English carols and the two sides shouted Christmas greetings to each other and soon made visits across the "No man´s land" exchanging small gifts.