Not a vast amount is known about the personal life of Wills Hill, 1st Marquess of Downshire (but always known as "Hillsborough"): he was one of the British statesmen thought to be most responsible for "losing" the American Colonies. So, to tumble across an original diary in Hillsborough's own fair hand - however fragmentary - was a stroke of luck. In this booklet the editor provides scans of the text and notes, together with an introduction and index of names.