Passage: From the age of seven, Cameron was educated at two independent schools: at Heatherdown School in Winkfield (near Ascot) in Berkshire, which counts Prince Andrew and Prince Edward among its old boys. Owing to good grades, Cameron entered its top academic class almost two years early. At the age of thirteen, he went on to Eton College in Berkshire, following his father and elder brother. His early interest was in art. Six weeks before taking his O-Levels he was caught smoking cannabis. He admitted the offence and had not been involved in selling drugs, so he was not expelled; instead he was fined, prevented from leaving the school grounds, and given a "Georgic" (a punishment that involved copying 500 lines of Latin text).Cameron passed twelve O-Levels and then three A-levels: History of art; History, in which he was taught by Michael Kidson; and Economics with Politics. He obtained three 'A' grades and a '1' grade in the Scholarship Level exam in Economics and Politics. The following autumn, he passed the entrance exam for the University of Oxford, and was offered an exhibition at Brasenose College.

Question: What age did Cameron initially receive education from?
seven