What was the yagna performed by Yudhishthira after the battle of Kurukshetra?

After winning the Kurukshetra war, Yudhishthira performed the Ashwamedha Yagna (horse sacrifice) to establish his imperial sovereignty over all kingdoms. This ancient Vedic ritual involved releasing a sacred horse to roam freely for a year, with kings either accepting Yudhishthira's supremacy or facing his army. Rajasuya was performed earlier before the war.