Christianity in Cornwall began in the 4th or 5th century AD when Western Christianity was introduced as in the rest of Roman Britain. Over time it became the official religion, superseding previous Celtic and Roman practices. Early Christianity in Cornwall was spread largely by the saints, including Saint Piran, the patron of the county. Cornwall, like other parts of Britain, is sometimes associated with the distinct collection of practices known as Celtic Christianity but was always in communion with the wider Catholic Church. The Cornish saints are commemorated in legends, churches and placenames.