Clavier entered the Bernard Gilpin Society, Sands House in Durham in 1958, leaving a year later to take a job as a teacher. In 1961, he was ordained a minister of the Countess of Huntingdon's Connexion. He then became involved in a number of independent Episcopal churches. He was ordained by Francis Everden Glenn to the Catholic Episcopal Church in 1962. In April 1963 he was ordained by Charles Dennis Boltwood of the Free Protestant Episcopal Church. In May 1963 he was ordained by Charles Leslie Saul of the English Episcopal Church. In 1965 he associated himself with Archbishop Gerard George Shelley of the Old Roman Catholic Church, only to leave and be ordained again by Hugh George de Willmott Newman of the Catholic Apostolic Church. He remained with that church until 1967 when he left for America.
Upon arriving in America, Clavier joined the Anglican Orthodox Church, staying with it until he returned to England and the Catholic Episcopal Church there.
In 1969 Clavier returned to the United States once again, seemingly to stay. He became a priest under James Hardin George of the American Episcopal Church. On 11 February 1970, George consecrated Clavier as a bishop and appointed him as a suffragan. Later that year, George resigned and Clavier served as primate for the next six years. Harold L. Trott became primate in 1976, only to leave office in 1981 with Clavier once again taking the position as primate.
In 1995, after allegations that he had attempted to have sexual relations with some female parishioners, Clavier resigned his position at the Deerfield Beach Anglican congregation and, in July 1995, the house of bishops subsequently declared that he had abandoned his vows and deposed him. The local standing committee refused to prefer charges against him. Clavier later joined the Episcopal Church as a priest.
- Why a New Church?, 1964
- False Motives, 1964
- English Old Catholicism, 1965