Here Boniface met Beatrice of Lorraine, niece and foster daughter of Empress Gisela of Swabia with whom a marriage covenant could be arranged. According to the agreements, Beatrice brought important assets in Lorraine: the Château of Briey and the Lordships of Stenay, Mouzay, Juvigny, Longlier and Orval, all the northern part of her paternal family's ancestral lands.
During their encounter, Boniface encountered Beatrice of Lorraine, a relative of Empress Gisela of Swabia, with whom a marriage pact could be formalized. As part of the agreement, Beatrice brought substantial assets to Lorraine, including the Château of Briey and several lordships that comprised the northern portion of her family's ancestral domain.