From Jerripedia
It is not known when the parishes were first created, but it is thought that it could have been as early as the 11th or 12th Century, and may have coincided with the building of the 12 parish churches.
The 12 parishes are:
- Grouville
- Saint Brelade
- Saint Clement
- Saint Helier
- Saint John
- Saint Lawrence
- Saint Martin
- Saint Mary
- Saint Ouen
- Saint Peter
- Saint Saviour
- Trinity
