Gilbert Declercq, who sometimes signed his work Gidecq, studied in Ghent and at the Famous Artists School. He began his career in Ons Volkske at the age of 16, with the realistic short story 'De D-558-2 Skyrocket'. He made illustrations in women's magazines, like Mimosa, Rosita, Libelle and Het Rijk der Vrouw. Declercq also worked for the animation studio of Raoul Servais in the 1960s and early 1970s. From 1971, he did illustrations and covers for Ohee. In Le Soir, he created 'Hugo des Ombres' with text by André-Paul Duchâteau in 1974. A year later, he illustrated the John Flanders adaptation 'De Witte Tijger' with text by Serge Bertrain (Danny de Laet) in Het Gazet Van Antwerpen. From 1974, he assisted Eddy Ryssack on his comics. In the late 1970s, he did comics for Top ('Devoon en Carboon') and Het Gazet van Antwerpen ('De Lotgevallen van Terry Trom'). He had his breakthrough with the aviation series 'Rud Hart', that appeared in the Dutch Eppo from 1977. For the publisher Lombard, he created 'Jody Barton' in 1991. He dropped most of his comics activities to devote himself to illustrating and painting. He is a regular contributor to the Dutch girls magazine Tina.