The Cornish language died out in the 18th century, unlike its linguistic kin, Welsh and Breton. There is an ongoing attempt to revive the language, so you’ll see signage in English and Cornish; nonetheless, with only a few hundred fluent speakers, Cornish is not something you are likely to hear: except for place names.
By Tre Pol or Pen Shall ye know all Cornishmen
Richard Carew, The Survey of Cornwall, 1602
Many place names incorporate Cornish prefixes and suffixes, such as Tre, Pol, and Pen, as these town names illustrate. Tre means a settlement or homestead (e.g., Treverbyn, Trethurgy, Treviscoe); Pol, a pond, lake, or well (e.g., Polgooth, Polruan, Polzeath); and Pena hill or headland (e.g., Penwithick, Penhale, Pentire). All examples were grabbed at random from a quick perusal of the Cornish map.
Many other town names commemorate Cornish saints.
Cornish saints
As we drove across the duchy, I began making a list of Cornish saints, but finally gave up: there are so many! There are, according to Wikipedia, around 60 saints are associated with Cornwall. Many of these were 5th or 6th-century missionaries from Ireland or Wales. The following lists but a few of that blessed multitude.
Patron saints
Cornwall may be small, but it has three patron saints, St Michael (St Michael’s Mount) and two missionaries:
Saint Piran, a 5th-century Cornish abbot and saint of Irish origin, is the patron saint of tin-miners. Perranporth is named after him.
Saint Petroc (French: Perreux) was a 6th-century Welsh prince who ministered to the Britons of Devon and Cornwall. He is also honored in Brittany (as are many Cornish saints), the town of Saint-Perreux being named after him.
St Ives (St Ia). Ia was late arriving at the Irish seashore to depart for Cornwall–as she was supposed to do with 777 other saints. Finding that they had gone without her, she 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. She and other Irish missionaries were martyred by the tyrant Tewdwr Mawr. The church of Plouyé in Brittany is also dedicated to her.
The Cornish towns of St Austell (Austol) and St Mewan (Méen) are named after 6th-century saints, from Wales, who spent most of their lives in Brittany. St Mewan founded the Abbey of Saint-Méen in Brittany.
St. Mawes ( Maudez and variants in Breton) is named after a 5th-century monk from Ireland, who traveled to Cornwall and then to Brittany, visiting monasteries and founding hermitages.
St. Kew is named after another Welsh missionary; she came to Cornwall with her brother Docco in the 5th century and founded a religious center.
St Breage or Breaca (with many variant spellings) is venerated in Cornwall and South West England. An Irish nun of the 5th century, she founded a church in Cornwall. The village and civil parish of Breage in Cornwall are named after her, and the local Breage Parish Church is dedicated to her.