In the early years of the revival of the Order of the Crown of Thorns (the last decades of the nineteenth-century) friendly contact was in place between the Order and the Royal House of Lusignan, several of whose members served as Patrons of the Order.

Now, in the twenty-first century, this relationship has been reconfirmed with the signing of Treaties of Friendship between the Abbey-Principality of San Luigi and two Orders of the Royal House of Lusignan, the Order of St Catherine of Mount Sinai and the Order of St Blaise.