The Military and Hospitaller Order of Saint Lazarus is one of the orders of chivalry to survive the downfall of the Kingdom of Jerusalem and the attempts by the Crusader knights to win control of the Holy Land from the forces of Islam. In theory the Order remained a military one, but with the exception of a brief period in the 17th century it played no military role after 1291. The Order of Saint Lazarus is one of the most ancient of the European orders of chivalry. At the very least it dates back to the time of the Crusader knights. From its foundation in the 12th century, the members of the Order were dedicated to two ideals: aid to those suffering from the dreadful disease of leprosy and the defense of the Christian faith.

Today the Military and Hospitaller Order of Saint Lazarus of Jerusalem is an international self-governing and independent body, having its own Constitution; it may be compared with a kind of electoral kingdom. According to the said Constitution the Order is nonpolitical, ecumenical or nondenominational, as its membership is open to all men and women being practicing members of the Christian faith in good standing within their particular denomination. Its international membership consists of Roman-catholic, Anglican, Protestant, Orthodox, United, Old Catholic, New Apostolic and other Christians, upholding with their lives, fortunes and honour the principles of Christianity. Traditionally it is organized as a Christian Chivalric Order. The Order is registered in London in accordance with the laws in England.

It is both a Military Order of Mercy and a Hospitaller Order dedicated to the care and assistance of the poor and the sick. Its aim is to preserve and defend the Christian faith, to guard, assist succor and help the poor, the sick and dying, to promote and maintain the principles of Christian chivalry and to follow the teachings of Christ and His Holy Church in all its works.

With the exception of the present Teutonic Order ("Deutscher Orden") the Order of Saint Lazarus is today the smallest of the orders of Christian chivalry. It is made up of approximately five thousand members in the five continents. The Order sees itself as an ecumenical Christian Order whose genesis goes back to the Holy Land, to the crusades and to the Kingdom of Jerusalem.