Yes, King Tutankhamun did go to war with another group of people. Specifically, he led a military campaign against the Nubians, a people who lived to the south of Egypt in what is now Sudan. The exact reasons for the conflict are not fully known, but it is believed that Tutankhamun wanted to secure Egypt's southern border and expand his kingdom. The campaign was successful, and Tutankhamun returned to Egypt as a victorious pharaoh. However, it is believed that he died shortly after this campaign, possibly from injuries sustained in battle or an accident while hunting.