Portaels was a student of Navel and Delaroche in Paris, and became the son in law of the former. He travelled around Europe and the Orient before completing his studies. Returning to Belgium he was made director of the Academy of Gand, then took up the same post in Brussels from 1876. In 1843 on a trip to Egypt and Palestine, he was one of the first Belgians to handle Orientalist subjects, becoming a considerable influence in Belgian art. He was made Chevalier de l'Ordre de Léopold in 1852. Museums in Brussels, Anvers, Liège, Sydney, and Philadelphia conserve his works.