 Otto assumed the Iron Crown of Lombardy at Pavia despite his rival Margrave Berengar of Ivrea.When in 960 Berengar attacked the Papal States, King Otto, summoned by Pope John XII, conquered the Italian kingdom and on 2 February 962 had himself crowned Holy Roman Emperor at Rome.From that time on, the Kings of Italy were always also Kings of Germany, and Italy thus became a constituent kingdom of the Holy Roman Empire, along with the Kingdom of Germany ("regnum Teutonicorum") and – from 1032 – Burgundy.