Today, 319 years ago, 38 members of the Clan Macdonald were killed in Glen Coe, when their guests, members of the Clan Campbell, turned on them. Glencoe, a spectacular mountain valley about 80 miles north of Glasgow, is now synonymous with this crime. the details of which are outlined on this Wikipedia article.
The involvement of King William III renders this a black mark on the conscience of the Dutch - he assumed the English throne when he came across from Holland as William of Orange. In the Netherlands, he is referred to as the Father of the Fatherland - translating directly. 23 years ago, there were extensive celebrations on the 300th anniversary of William's marriage to Queen Mary II of England. This lasted for 6 years, until Mary's death in 1694.
William III has another black mark on his record, commonly referred to as the Battle of the Boyne. This battle, which took place on Irish soil in 1689, has been used as a pretext by extremist sections of the Protestant and Catholic communities in (Northern) Ireland for acts of violence in the 20th century.
Mind you, if you think that is bad, it is worth bearing in mind that the war in the Balkans in the 1990s was justified by Serbia's president Slobodan Milosevic on account of the Battle of Kosovo in 1390.