According to the Vita Gudilae (recorded between 1048–1051) he followed his brother Henry I of Louvain as Count of Leuven.
Lambert scorned both temporal and spiritual authorities and in 1054 even took up arms against Holy Roman EmperorHenry III. He was defeated and lost his life at Tournai.
During his reign Brussels began its growth. Lambert arranged to transfer the remains of Saint Gudula to the St. Michael's church. This church, thereafter known as the Saints Michael and Gudula Church, later became the St. Michael and Gudula Cathedral. Lambert also constructed a fortress on the Coudenberg hill.
Lambert II died in 1054.
Family
Lambert of Louvain married Uda of Lorraine (also called Oda of Verdun), daughter of Gothelo I, Duke of Lorraine.[2] Their children were: