During the Middle Ages from the 11th to 15th centuries, Catholicism dominated religion in Europe. Thomas Aquinas was an influential Catholic priest whose works Summa Theologica explored theological issues. Art during this period was influenced by Byzantine, Roman, and Northern European styles and was largely produced by monks. Notable art forms included tapestries, sculpture, painting and music like Gregorian chants and works of later composers. Feudal society was hierarchical and stratified with the king, clergy, and nobility at the top. Literature works were mostly religious or about courtly love and notable authors included Dante, Chaucer, and the anonymous author of Beowulf.