Devshirme was a system in which

The Devshirme system was a system where Christian boys were recruited by force to serve the Ottoman government.

Devshirme was a system in which young Christian males were required to serve the Ottoman sultan.

Devshirme was chiefly the practice where the Ottoman Empire sent military officers to recruit Christian boys, ages 8 to 18, from their families in Eastern and Southeastern Europe in order that they be raised to serve the state.

After that, the boys were converted to Islam.

This practice formally ended by the middle of the seventeenth century.