Guillaume III de Lamboy de Dessener, 1590 to 1659, was a Field Marshal, in the Imperial Army, who served in the 1618 to 1648 Thirty Years War, and the 1635 to 1659 Franco-Spanish War.
Born in Kortessem, then in the Spanish Netherlands, now Limburg, Belgium, Lamboy was a member of the Catholic, French-speaking, Walloon nobility. During the Dutch Revolt, they remained loyal to the Habsburg rulers of Spain and the Holy Roman Empire.
In 1636, he commanded Imperial troops during a nine month siege of Hanau, before being forced to retreat, an event still commemorated each June in the Lamboyfest.
He retired from active service after the 1648 Treaty of Westphalia, and settled in Bohemia, where he died 12 December 1659.