Ia of Cornwall

Saint Ia of Cornwall (also known as "Eia", "Hia" or "Hya") was an evangelist and martyr of the 5th or 6th centuries in Cornwall. She is said to have been an Irish princess, the sister of Erc of Slane and a student of Saint Baricus.
Legend.
Ia went to the seashore to depart for Cornwall from her native Ireland along with other saints. Finding that they had gone without her, fearing that she was too young for such a hazardous journey, she was grief-stricken and began to pray. As she prayed, she noticed a small leaf floating on the water and touched it with a rod to see if it would sink. As she watched, it grew bigger and bigger. Trusting God, she embarked upon the leaf and was carried across the Irish Sea. She reached Cornwall before the others, where she joined Saint Gwinear and Felec of Cornwall.
Legend holds that they had up to 777 companions. She is said to have founded an oratory in a clearing in a wood on the site of the existing Parish Church that is dedicated to her. Ia was martyred under "King Teudar" (i.e., Tewdwr Mawr of Penwith) on the River Hayle and buried at what is now St Ives, where St Ia's Church—of which she is now the patron saint—was erected over her grave. The town built up around it. Her feast day is 3 February.
A now ruined chapel near Troon was dedicated to her. The church of Plouyé in Brittany was probably dedicated originally to this saint. John Leland gives details from a Latin hagiography of Ia, which is no longer extant.