Also known as the Chain of Esses, Livery Collar or Chain of Office, the chain is made up of several elements: the Red Rose, the Welsh knot and the portcullis. Together these represent England, Wales and the Crown.
The only questionable element, strangely, is the source of the Ss themselves. It was thought that the S's were devised by Henry IV to stand for his motto or 'word of Soverayne', but that theory may be disposed of by the effigy of Sir John Swynford in Spratton Church, who died in 1371. His is the oldest effigy bearing the chain but hasn't put paid to further speculation of its source - another theory relates it to the phrase 'Souvient me souvien' or 'Think of me often'. The collar was also a royal badge of the Lancastrian house and party and it is said that the Duchy of Lancaster passed his on to the Chief Justice of England as a gift in the 1600s; from around this time onwards the wearing of a chain of Ss by the Lord Chief Justice of England & Wales became tradition.
The effigy of Sir John Swynford, Spratton Church, 1371
In modern times the Collar of S's is worn on state occasions only by the Kings and Heralds of Arms, by the Lord Chief Justice and by Serjeants-at-Arms.