The Shire Hall in Lancaster Castle contains a collection of heraldry which is probably unique in the British Isles, containing as it does over 600 shields bearing the arms of all the sovereigns of England, the Constables of Lancaster Castle and the High Sheriffs of Lancashire from 1189 to 2000. This book contains a description of all the shields in full heraldic terms. The book is a must for anyone interested in heraldry or wishes to learn more on the subject.