For many centuries the Catholic Church created various rites to bless new kings and queens throughout Europe. These rites were different in each country, but all shared similar prayers to bless a new monarch.
Here is an English translation of a Latin prayer that is attributed to Archbishop Egbert of York (732-766), according to the Catholic Encyclopedia.
O God, who providest for Thy people by Thy power and rulest over them in love;
grant unto this Thy servant....our King, the spirit of wisdom and government,
that being devoted unto Thee with all his heart, he may so wisely govern this kingdom,
that in his time Thy Church and people may continue in safety and prosperity,
and that, persevering in good works unto the end,
he may through Thy mercy come to Thine everlasting Kingdom;
through Jesus Christ Thy Son our Lord. Amen.
