Born  20 December 1901 at Jemeppe -Sur - Sambre. Moved to Nivelles in 1920. Engaged into Aéronautique Militaire where he gained his wings on 1 August 1923. Hed led a two year Belgian mission to Iran in 1934, to reorganise the Persion Military Aviation. During the invasion of Belgium, Guillaume was first send to Caen for the reception of the first Brewster B-339, with no succes, the Cargo Ship being diverted to Bordeaux due a harbor strike. Here the shipment was also unsuccesfull due the fast German advance. He demobilised end August. Known for his anti-nazi opinions, he had to escape  from Belgium on 17 December 1940 (with Pierre Vandermies). He arrived in the UK on 9 April 1941. Engaged the RAFVR, get a short training, get a commision and was posted  to 131 Sqn (26/08/1941), 78 Sqn (26/10/41), 615 Sqn, .... Took command of 350 Sqn from 20/03/42 till 19/12/42. He took command as station commander of RAF Hornchurch, became instructor at Old Sarum, led the Belgian Initial Training school and ended the war as G/Cpt, being Inspector of the Belgian Air Force in GB. After the war he became the major of the City of Nivelles. He died on 26 January 1988.

(source: Nicolas Clinaz)