Catholic Archbishop Barry Hickey has resigned before his 75th birthday this month after 20 years leading the Archdiocese of Perth.
Under Church law, all bishops must resign when they turn 75.
Archbishop Hickey will stay in the job until the Pope accepts his resignation, which lapses if not accepted within three months.
His resignation is historic for the Church in Perth after two decades under his leadership, during which he was an outspoken advocate of social welfare issues and prominent supporter of charities.
Born at Leonora in 1936, Archbishop Hickey went to Presentation Sisters and Christian Brothers schools at Wiluna and Kalgoorlie before attending St Charles Seminary in Guildford in 1950.
He was ordained in Rome in 1958 and was assistant priest at St Brigid's Parish, West Perth, until 1965 before becoming Bishop of Geraldton in 1984 and Archbishop in August 1991.
Under him, St Mary's Cathedral was refurbished over a decade until it reopened in December 2009.
He helped establish numerous charities such as LifeLink, Linda's House of Hope, The Shopfront and Aboriginal advocacy Daydawn.
The Archbishop has courted controversy, wading into the stemcell research debate and questioned Julia Gillard's atheism before the last Federal election.
It could be a year before Perth finds out who will replace him but there is little doubt about front-runners Auxiliary Bishop of Perth Don Sproxton, 58, and Bishop of Bunbury Gerard Holohan, 63. Both are well liked, are local clergy and are in the right age range.
Bishop Holohan, who oversaw building Bunbury's cathedral, has an academic background focused on education and was a director of religious education for Perth, Geraldton, Bunbury and Broome.
Bishop Sproxton has been more involved in parish life. A former chaplain to Royal Perth Hospital and Trinity and Mercedes colleges, he has popular appeal.
Other possibilities, Geraldton's Bishop Justin Bianchini, 70, and the Dean of St Mary's Cathedral, Mgr Michael Keating, 71, are out of contention due to their age.