In the 16th and 17th centuries the Order had religious houses in northern Italy and Spain; the members, who were mostly professed knights, carried out works of charity.  Even before the acquisition of the grand mastership by Francesco Farnese, knights of the Order had been engaged in the defense of Vienna under command of King Jan Sobieski; then, under Francesco Farnese it took on a larger military mission, establishing a military college to train young officers. The Constantinian Regiment sent in 1716 to fight the Ottoman occupation of the Balkans under the supreme command of Prince Eugene of Savoy earned the Order praise and further privileges. The Order provided support for the poor and sick in southern Italy during the 18th and 19th centuries and, after the unification of Italy, it established youth groups, taking on many activities in support of the Church which, with Italian unification, had suffered considerable persecution and the confiscation of its property.  In the First World War it provided first aid and help to prisoners of war, a task it repeated during the Second World War, when it assisted with the return of prisoners of war, working with the Allied Command in Southern Italy (the Allied Military Governor, Major General Erskine Hume, U.S. Army, was a grand cross of the Order). It repeated this task at the time of the breakup of Yugoslavia, while also assisting refugees from the conflicts in Syria and Iraq. The Order awards scholarship to seminarians in Italy and Spain, and recently contributed to a seminary in Mali, it provides humanitarian aid to Christian communities in the Middle East, and it has given direct aid to the victims of recent earthquakes in Italy and other natural disasters. In May 2017 it organized a special exhibition in Barcelona in conjunction with the Spanish Ministry of Education about the reign of King Charles III of Spain, who was Grand Master of the Order from 1731-59 (when he resigned the grand mastership to his son, later King Ferdinand I of the Two Sicilies). See  

The Order’s spiritual life is central to its existence, with regular monthly Masses organized by the Italian regional delegations, while the royal commissions in Italy, Spain and Portugal carry out many other activities in support of the Church.  The newer royal commissions of France, Luxembourg, Great Britain, Austria and Liechtenstein, and the United States are expanding activities to assist the spiritual life of the members, as is expected of the regional delegations in Germany, Scandinavia and Hungary. The major feast days of the Order are St. George’s Day (April 23) and the Exaltation of the Cross (September 14).