William Dempster was the son-in-law of James Ker. Ker is without doubt one of Edinburgh and indeed Scotland's most important and prolific goldsmiths. Working in the heart of Edinburgh's 'Golden age'. He, and within partnership with his son-in-law William Dempster as Ker & Dempster, made some of the most important mid-18th century Scottish plate known to survive including fine bullet tea pots and ovoid coffee urns in addition to the gold Leith race prizes which bear their mark. It is obvious they held a position of power within the capital and nation's trade. Their list of clients must be considered amongst the most impressive of any Scottish goldsmiths and include the Duke of Gordon, Earl of Breadalbane, Marquess of Lothian and perhaps most importantly various members and generations of the Hopetoun family.