Wikepedia.
St Pancras was originally a medieval parish, which ran from close to what is now Oxford Street north as far as Highgate, and from what is now Regent's Park in the west to the road now known as York Way in the east, boundaries which take in much of the current London Borough of Camden, including the central part of it. However, as the choice of name for the borough suggests, St Pancras has lost its status as the central settlement in the area. The district now encompassed by the term St Pancras is not easy to define, and usage of St Pancras as a place name is fairly limited.
Old St Pancras Parish Church.
The original focus of St Pancras was St Pancras Old Church, which is in the southern half of the parish, and is believed by many to be one of the oldest sites of Christian worship in Great Britain. However, in the 14th century the population abandoned the site and moved to Kentish Town, probably due to flooding by the River Fleet, which is now underground, and the availability of better wells at Kentish Town. The old settlement was abandoned and the church became derelict by 1847.
In the 1790s Earl Camden began to develop some fields to the north and west of the Old Church as Camden Town, which has become a better known place name than St Pancras. In the mid 19th century two major railway stations were built to the south of the Old Church, one of them called St Pancras and the other King's Cross. A residential district was built to the south and east of the church, but it is usually known as Somers Town. The term St Pancras is sometimes applied to the immediate vicinity of St Pancras Station, but King's Cross is the usual name for the area around the two mainline stations as a whole.
In 1822 the new church of St Pancras on Euston Road was dedicated as the parish church, and by the end of the century the ancient parish had been divided into 37 parishes, including one for the rebuilt Old St Pancras Church. There are currently 17 Church of England parishes completely contained within the boundaries of the ancient parish, all of whom benefit from the distributions from the St Pancras Lands Trust, and most of which are in South Camden Deanery in the Edmonton Area of the Diocese of London. The present Vicar, the Revd Anne Stevens, is the first woman vicar of St Pancras, and the first woman Church of England vicar in the very conservative Deanery of South Camden. St Pancras Parish Church is Grade 1 listed, and famous for its Greek revival style and the annual London Festival of Contemporary Church Music.