Before 1906, when the Senussi became involved in resistance against the French, they had been a "relatively peaceful religious sect of the Sahara Desert, opposed to fanaticism". In the Italo-Turkish War  Italian forces occupied enclaves along the Libyan coast and the Senussi resisted from the interior, maintaining generally friendly relations with the British in Egypt. In 1913, the Italians had been defeated at the Action of Etangi but in 1914 Italian reinforcements led to a revival and by January the Senussi were in south-eastern Cyrenaica. The Senussi had about 10,000 men armed with modern rifles, with ammunition from a factory which produced 1,000 rounds a day. Intermittent fighting continued between the Italians in fortified towns and the Senussi ranging through the desert. The British declared war on the Ottoman Empire on 5 November and the leadership of the Ottoman Empire encouraged the Senussi to attack Egypt from the west. The Ottomans wanted the Senussi to conduct operations against the rear of the defenders of the Suez Canal; the Ottomans had failed in previous attacks against British forces from Sinai in the east and wanted them to be distracted by attacks from the opposite direction.

Based on the above article, answer a question. How many years passed from when the Senussi became involved to when  the Italians had been defeated?
7