The Royal Mail traces its history back to 1516, when Henry VIII established a "Master of the Posts". The Royal Mail service was first made available to the public by Charles I in 1635, with postage being paid by the recipient, and the General Post Office was officially established by Charles II in 1660.
Between 1719 and 1763, Ralph Allen, Postmaster at Bath, signed a series of contracts with the post office to develop and expand Britain's postal network. He organised mail coaches which were provided by both Wilson & Company of London and Williams & Company of Bath. The early Royal Mail Coaches were similar to ordinary family coaches but with Post Office livery.
http://en.wikipedia.org/wiki/Royal_Mail#Histor y