Coins minted in the Year 1757

What happended in 1757?
Monarch is George II. Prime Minister is William Cavendish, 4th Duke of Devonshire (Whig), then on 2nd July it is Thomas Pelham-Holles, 1st Duke of Newcastle (Whig). The  Seven Years' War continues. 1757 is MDCCLVII.
Obv Rev Cat Coin
  Sixpences 1757 Sixpence - George II