Background
He was the youngest son of Charles de Berlaymont and Adriana de Ligne Barbançon, and brother of Gilles de Berlaymont and Claude de Berlaymont.
He was the youngest son of Charles de Berlaymont and Adriana de Ligne Barbançon, and brother of Gilles de Berlaymont and Claude de Berlaymont.
In 1576 Florent shortly joined the Union of Brussels, but soon became loyal to the King of Spain again. Florent inherited the title of Count of Berlaymont from his father in 1578. By marrying Margaret of Lalaing, only daughter of Philip de Lalaing (1537-1582) and Margaret of Ligne, he als became Count of Lalaing in 1582.
Florent and Margaret of Lalaing also had only one daughter, Margaret of Berlaymont, who married Louis of Egmont, prince of Gavere (died 1654).
In 1604, Florent also became stadtholder of Luxembourg, after the death of Peter Ernst I von Mansfeld-Vorderort.