The High Septon, also known as 'His High Holiness', is the supreme priest of the Faith of the Seven. The office holder originally resided in Oldtown until the invasion of Aegon the Conqueror, when he moved to the new capital of King's Landing. He currently resides in the Great Sept of Baelor.
The High Septon wears a large crown made of crystal. He gives up his family name and any family connections, as he is now seen as an avatar of the Gods.