The three previous notes in this series have presented die studies for the third issue shillings with mintmarks Rose, Thistle and Lis. This note will finish off the third issue with a die study of the shillings with a trefoil mintmark. A total of 63 specimens have been noted from 36 obverse and 47 reverse dies and a statistical analysis suggests that as many again are yet to be discovered.
As the last mintmark of the reign, the trefoil continued to be used for a few months into the reign of Charles I and two Pyx trails were carried out on 7 July 1625, the first for coins struck whilst James I was alive and the second for posthumous issues. This note also identifies a group of dies that might be associated with the posthumous issues.
Extrapolating from the Rose, Thistle and Trefoil data allows an estimate to be made of the amount of silver at the previous Trial of the Pyx for coins bearing the mm Lis, a number that is absent from contemporary records.