Mail communication between London and Ireland was very important for both official and trade purposes from the 15th Century. From the mid 16th Century a number of designated ports were used to ship the mail to Ireland and posts were laid to those ports along defined routes, however, these routes were subject to change. This book identifies the ports, when they were used and presents the history of the changes to those routes from that early time until 1850. Detailed descriptions of the routes are given in text, tables and figures showing how they changed over these years, together with a discussion of those changes and a commentary on the improvements that were made to the roads over the years, particularly in the difficult areas of North Wales, South Wales and South West Scotland. Also included is the history of the Edinburgh to Portpatrick route. Finally the effect of the introduction of the railways on the carriage of mail to Ireland is described.