Index to Butlers investigated in the course of my researches.  Prior to Daniel Butler moving to London around 1745, these Butlers were based in the corner where Hertfordshire, Buckinghamshire and Bedfordshire meet.

(Map courtesy of Google)

The parish map for this area (Phillimore atlas and index for Bedfordshire, Buckinghamshire and Hertfordshire) is complex - unfortunately it cannot be reproduced for copyright reasons.