Floris was the son of Frederik van Egmond and Aleida van Culemborg. His career started in the 1490s as a chamberlord in the royal household of Philip I of Castile. After Philip's death, Floris gained a seat in the Court Council of Margaret of Habsburg, at the time the governor of the Netherlands. In 1505 he was knighted in the Order of the Golden Fleece.
As a stadtholder of Guelders, he represented the Habsburg government in the parts of Guelders owned by Magaretha.
In 1515 he became stadtholder of Friesland, when it was sold by George, Duke of Saxony to Habsburg. George of Saxony had failed to subdue Friesland during the Guelders Wars, and Floris controlled only a few cities (Leeuwarden, Harlingen and Franeker).
Floris was also a commander in arms. In 1523, he was appointed commander of the Dutch troops for an invasion of France during the Italian War of 1521–1526. In 1536, Floris became Captain-General of the Army that was present in the northern parts of the Low Countries.
Floris van Egmond married Margaret of Glymes-Bergen, daughter of Cornelis of Glymes, on 12 October 1500. They had two children:
Cools, Hans, "Florent d'Egmont et Adrien de Croÿ, les carrières exemplaires de deux chefs de guerre de Charles Quint", in Cauchies, Jean-Marie & Guisset, Jacqueline (eds.): Du métier des armes, à la vie de cour, de la forteresse au château de séjour. Familles et demeures aux XIVe-XVIe siècles. Turnhout : Brepols, 2005, ISBN2-503-52220-3, p. 205-216.
