Complex sentence: After briefly attending classes at the Académie Julian and working in the studios of Marcel Baschet and Lionel Royer, he enrolled at the École nationale supérieure des Beaux-Arts.
Split into simpler sentences: After briefly attending classes at the Académie Julian, he worked in the studios of Marcel Baschet and Lionel Royer. Then, he enrolled at the École nationale supérieure des Beaux-Arts.