Cannes, 14 December 1900 - Deed of Cannes, by which H.R.H. Prince Don Charles of Bourbon Two Sicilies solemnly renounced -for himself and his heirs - all rights on the Royal House of the Two Sicilies and became member of the Royal House of Spain (1900).

Madrid, 7 February 1901 - Official Deed of the Kingdom of Spain by which H.R.H Prince Charles of Bourbon became member of the Royal House and Family of Bourbon - Spain.

Rome, 20 July 1963 - Letter by the Minister of Foreign Affairs on the authorisation to Constantine Knights to use the insignia.

Rome, 30 March 1973 - Decree of the President of the Republic by which the National Italian Association of the Knights of the Sacred Constantine Order of St. George was established as non-profit corporation.

26 November 1981 - Decision n. 1869/'81 by the State Council of the Italian Republic, concerning the Sacred Military Constantinian Order of St. George, its legal status and use of its decorations.

Rome, 5 May 1986 - Letter of thanks by the President of the Republic Francesco Cossiga to H.R.H. Prince Ferdinand of Bourbon Two Sicilies, Grand Master.

Rome, 23 May 2001 - Letter by the Head of the Diplomatic Protocol of the Republic to H.E. Prince Paolo Boncompagni Ludovisi, President of the Royal Association of the Sacred Military Constantinian Order of St. George, on the use of the decorations of the Order.