St David's Cathedral could become the first Church in Wales site to elect a woman bishop as voting for a new incumbent begins.
An electoral college of 47 people from across Wales will spend up to three days locked in the cathedral from Tuesday while they make their decision.
The decision follows the retirement of Wyn Evans.
The new bishop will be the 129th Bishop of St Davids. There has been a church on the site since the 6th Century.
St Davids diocese includes the west Wales counties of Pembrokeshire, Carmarthenshire and Ceredigion.
The decision to allow women bishops was made following a landmark vote in September 2013.