The first postmarks
The very first postmark in the world was the invention of Colonel Henry Bishopp (or Bishop or Bisshopp) (1605-91) in 1661. He had bought the monopoly for delivering letters around the country and had become the first ‘Postmaster General’ in Britain.
He wanted a method of recording the date each letter was handed in to the post office. This was because of complaints from customers about delays in delivery. His ‘bishopmark’ provided the means of better organising the delivery schedules.
The bishopmarks were approximately half an inch diameter black circles with the month and the day inside. Each wooden stamper was chiselled individually in the first year and kept for re-use thereafter.
Postmarks, as they later became known, have been used ever since and the idea spread across the world. Later on, they also showed the year and the town where the posted item was handed in or sorted and, with the introduction of postage stamps, they also served to mark those stamps so that they could not be re-used for free!
(Images LtoR: Col. Bishop and his bishopmark at Wikimedia Commons / Public domain & Alwyn Ladell at Flickr.com / CC BY-NC-ND 2.0)