collar of esses

noun1

1. •
   An ornamental chain made up of interlinked or juxtaposed S's, originally worn by nobles of the House of Lancaster, and later associated by some writers with the Order of the Garter.

   • Anciently, the creation of an esquire, in England, was performed by the ceremony of the King placing about his neck a silver collar of SS, as an ensign of that dignity […]. — 1828