The Battle of Tong Vey was a battle that took place at the Klingon city of Tong Vey.
Ten thousand Klingon soldiers sieged Tong Vey and, once the city had fallen, Emperor Sompek ordered the inhabitants to be put to death and the city burned. (DS9 episode: "Rules of Engagement")
The Battle of Tong Vey also occurred in the alternate universe and was commemorated in the Klingon opera Sompek's Revenge. (ST novel: Dark Passions)