Pope Benedict XVI (L) shakes hands with a woman next to Knights of the Order Malta Grand Master Matthew Festing after the mass in St.Peter's Basilica to mark the 900th anniversary of the Order of the Knights of Malta, on February 9, 2013 at the Vatican

Pope Benedict XVI met with around 4,000 members and volunteers of the Order of Malta at the Vatican on Saturday in a special ceremony marking 900 years since the famous crusading order was placed under papal protection.

The order was created to provide care for poor and sick pilgrims to the Holy Land. It also goes by the name of the Sovereign Military Hospitaller Order of St John of Jerusalem of Rhodes and of Malta.

"Because of their faith, and through the centuries, members of your order have helped the sick of Jerusalem, then pilgrims exposed to grave danger in the Holy Land," the pope told the group in a speech.

"In the 19th century, the order opened up and widened its assistance to the poor and the sick but without ever renouncing its original ideals. Your commitment must continue in this direction ... you must never forget your roots," he said.

The order was founded in 1048 but it was in 1113, after the Christian conquest of Jerusalem, that Pope Paschal II issued the Bull Pie Postulatio Voluntatis giving the knights the protection of the Church and assigning the order sovereign status to freely elect its superiors.

Following the loss of Jerusalem by Christian forces, the order operated from Rhodes, and later from Malta until moving to Rome in 1834.

The order has some 13,500 members -- assisted by 80,000 permanent volunteers and 25,000 medical staff -- engaged in humanitarian and medical relief work in more than 120 countries around the world.