Johann Gabriel Josef Albert, Marquess of Chasteler and Courcelles was a Walloon, born near Mons, Belgium. He entered the military service of Habsburg Austria at an early age and trained as an engineer at the Ingenieurakademie in Vienna. Serving as chief of staff to Spleny in the Turkish War from 1788, he won the Ritterkreuz of the Order of Maria Theresa for outstanding bravery at the Battle of Focsani in action against the Ottoman Turks.

Count Albert Gyulay de Marosnémethi et Nádaska or Albert Gyulai von Máros-Németh und Nádaska, born 12 September 1766 – died 27 April 1835, a Hungarian, joined the army of Habsburg Austria and fought against Ottoman Turkey. He served against the First French Republic in the Flanders Campaign and on the Rhine. Severely wounded in 1799, he survived a trepanning operation and briefly retired from military service. He returned to active service and commanded an army corps during the War of the Fifth Coalition, part of the Napoleonic Wars. He led his troops in several important battles during the Austrian invasion of Italy in 1809, including one where he was in independent command. Though appointed to command troops in 1813 and 1815, he missed combat in both campaigns. He was Proprietor (Inhaber) of an Austrian infantry regiment from 1810 until his death. The more famous Ignác Gyulay, Ban of Croatia was his older brother.