Simplify the following text for a Grade 9 native English-speaking person.
Original: He went to the Royal Swedish Academy of Arts between 1947 and 1952 , when he began to illustrate Swedish classical books such as those written by Per Anders FogelstrÃ m.
Simplified: He attended the Royal Swedish Academy of Arts between 1947 and 1952 , during which time he began to illustrate Swedish literature such as the novels of Per Anders FogelstrÃ m. Claesson was the father of actor Leif Claesson .