The village of Portbail is located on the edge of a natural harbor bordered by dunes on the south side and herbus where graze pre-salt north side. The two churches (one at the edge of the harbor, the other about 200 m away), corresponded to two separate parishes: Portbail (at the edge of the harbor) and Gouey (further inland). It is the church of the latter which became the parish church of Saint Martin. Portbail was a trading port in the Gallo-Roman and early Christian era, then a land Viking installation, the latter having quickly acculturated.