The Kingdom of Dál Riata (also spelled Dalriada) included parts of western Scotland and northeastern Ireland. According to legend, it was founded by the three sons of Erc— Fergus Mór, Loarn and Óengus, through conquest sometime in the 6th century AD, and it lasted well into the 8th century. Dál Riata is probably best known for the monastery of Iona, founded by the monk Columba in 563. Iona was a very important center of religion. learning and art, and is credited with the formation of an artistic style known as Insular Art, which combined Mediterranean, Anglo-Saxon, Celtic and Pictish elements. The Book of Kells, probably produced at Iona, is one of the best examples of this style. Dál Riata was also known for its fine metal work, most notably for a distinct style of penannular brooch.