The history of Luxembourg properly began with the construction of Luxembourg Castle in the High Middle Ages. It was Siegfried I, count of Ardennes who traded some of his ancestral lands with the monks of the Abbey of St. Maximin in Trier in 963 for an ancient, supposedly Roman, fort named Lucilinburhuc.[16] Modern historians explain the etymology of the word with Letze, meaning fortification which might have referred to either the remains of a Roman watchtower or to a primitive refuge of the early Middle Ages.