There was a great rebellion in England from 1642 until 1649. During that rebellion there was a siege at Newark-On-Trent that lasted for one full year. As sieges do, there was great suffering in the surrounding area, and also, money to be made. Supplies were required and wages needed to be paid and spent.
This coin was minted for just that purpose. It was made in Crown, Shilling, Ninepence, and Sixpence denominations, all with the same design. Although made specifically for use in the siege region, it was a coin of the realm and was accepted throughout the neighboring countryside.