They are first recorded in 6th-century historiography as having been allied with the Goths in the invasion of Dacia in c. 260. In the 4th century, they were incorporated into the Hunnic Empire. Under their leader Ardaric, the Gepids united with other Germanic tribes and defeated the Huns at the Battle of Nedao in 454. The Gepids then founded a kingdom centered on Sirmium, known as Gepidia, which was defeated by the Lombards a century later. Remnants of the Gepids were conquered by the Avars later in the 6th century.[citation needed]