The Royal Mail in the UK has been issuing series of special stamps for over 50 years, starting in 1965 with Sir Winston Churchill.
     Their current series is dedicated to Ancient Britain. It is a series of 8 stamps of varying denominations, each depicting either an actual famous artefact or a site, from across the Neolithic & Mesolithic Eras, Bronze and Iron Ages, with modern graphic additions to place them in context. For example, an Iron Age shield, known as the Battersea Shield after the location where it was found, is shown as being held by an Iron Age warrior.
     Other artefacts depicted are the Star Carr Headdress, Drumbest Horns and the Mold Cape, all shown as they would have been worn. The sites depicted show the Grimes Graves Flint Mines, Avebury Stone Circles, Maiden Castle Hill Fort and Skara Brae village, all being given some graphical treatment to  bring them to life. Whilst being legally useable the stamps are not intended for general postal use but more as a presentation pack for collectors.

Edited from  Royal Mail (December 2016), Norvic Philatelics (21 Dec 2016)