Born in Paris, de Dreux was the only son of noted architect Pierre-Anne Dedreux. He studied under Theodore Gericault and Leon Cogniet. He first exhibited at the Salon in 1831, and his equestrian portraiture landed him an invitation to accompany King Louis-Phillippe to England. After the king’s exile, he also painted the portraits of Emperor Napoleon III and his family along with many other equestrian portraits of British aristocracy.