In 1910, the school started to use the word "Lise" (Lyceum), a first in a Turkish school. İstanbul Lisesi was a 5-year boarding school charging tuition, and was admitting students following an examination. The physical education teacher of the school, Abdurrahman Roberson, established İstanbulspor and a boy scout group in 1912. The scout group, later named Sakarya in honor of the Turkish victory in Battle of Sakarya, is still active to this day. Also in 1912, during the First Balkan War, about 30 students volunteered for the defense of the capital against the advancing Bulgarian army.