These distribution maps use Baptism Marriage and Burial data extracted from parish registers. The prime source of the dataset is the IGI but includes events extracted my myself. Most of  the IGI data used has been checked to parish registers, no data has been used that is not included in the main database.The cut-off of June 1837 has been applied as subsequent data is available from civil registration indices, a separate dataset 1837 - 1937 is provided. Variants prior to 1837 were not constant even amongst families therefore the main distribution maps do not take account of these. There is however one dataset produced that indicates the earliest records of each of the four variants that persevere into the 20^th century with detail for London, Northumbria and the Midlands.