Gesalic was king of the Visigoths from 507 through 511. He was the illegitimate son of Alaric II. When Alaric was killed in battle by the Franks, his only legitimate son, Amalaric was a child. The Visigoths, who did not have primogeniture elected Gesalec to reign. Although he pursued the war against the Franks, he was not successful and the Franks burned his capital at Toulouse. After Narbonne fell to the Burgundians, Gesalic's Visigoths fell back to Iberia and the Ostrogothic king Theodoric came to his assistance.

In 511, Gesalic was driven from the throne by Ibbas and fled to Africa. He attempted to get aid from the Vandals and the Ostrogoths, but failed. Eventually he launched an invasion of Spain from Aquitaine, but was defeated by Ibbas's army and killed at the end of the year. Theodoric acted as regent for Gesalic's half-brother, Amalaric, until Alamaric was old enough to take the throne.