FYI, they are not per se "Catholic" Knights - The Sovereign Military Hospitaller Order of Saint John of Jerusalem of Rhodes and of Malta. The roots of the current organization lie in what was an actual Catholic religious order, but the current organization and the bulk of its members is and are not Catholic religious.

The present charitable organization has reestablished ties with the Bailiwick of Brandenburg of the Chivalric Order of Saint John of the Hospital at Jerusalem, the German Protestant branch of the Knights Hospitaller, which is the center of Protestant continuations of the Knights in Germany,  Austria, Finland, France, Hungary, and Switzerland, with the Most Venerable Order of the Hospital of Saint John of Jerusalem in the UK, the Swedish Johanniterorden i Sverige, and the Dutch Johanniter Orde in Nederland, and formed the Alliance of the Orders of St. John of Jerusalem.

This allows them to further their charitable efforts more widely and efficiently.