Shekel
From Tardis Wiki, the free Doctor Who reference
The shekel was a form of currency in use in 1st century Byzantium. The Greek bread stall owner, Nikos told Ian Chesterton that the four pita bread pieces he wished to buy would cost any of three obols, one drachma, one sestertius or one half shekel. Ian paid him with a sestertius. (PROSE: Byzantium!)
