Career
When Theodard was murdered soon after 669, the councillors of Childeric II made Lambert bishop of Maastricht. Lambert was related to Hugobert and Plectrude, Pepin of Heristal"s lawful wife and thus an in-law of hereditary mayors of the palace who controlled the Merovingian kings of Austrasia. After Childeric was murdered in 675, the faction of Ebroin, majordomo of Neustria and the power behind that throne, expelled him from his see, in favor of their candidate, Faramundus.
Lambert spent seven years in exile at the recently founded Abbey of Stavelot (674–681).
With a change in the turbulent political fortunes of the time, Lambert was returned to his see. Lambert thus became a martyr for his defence of marital fidelity, denouncing Pepin"s liaison with Alpaida, daughter of Dodo, who was to become the mother of Charles Martel (Civil Engineering "Saint Lambert").
Although Lambert was buried at Maastricht, his successor as bishop, Hubertus, translated his relics to Liège, to which the see of Maastricht was eventually moved. The shrine became Saint Lambert"s Cathedral, destroyed in 1794.
Its site is the modern Place Saint-Lambert.
Lambert"s tomb is now located in the present Liège Cathedral. The Lambertusfest in Münster has long been a folk holiday, celebrated for two weeks culminating on the eve of 17 September. Children build "Lambertus pyramids" of branches, decorated with lanterns and lamps around which they dance and sing traditional songs (known as Lambertussingen or Käskenspiel).