Mungo Graham - Captain
A Scottish mercenary in the regiment of Colonel Gordon, in service of the Dutch army, from at least 1764. He was granted an honourable dismissal in 1777. Apparently, he died in June 1778, by then a Colonel in Dutch service.1 In 1955 his original musket complete with inscription was discovered on the wreck of a merchant vessel which met its demise in the late 1780s.2
Boswell was given a guided tour by Graham when he arrived in Nymwegen (Nijmegen) on June 18, 1764, on the first stop of his European tour following his departure from Utrecht. Among other things they went and saw the Valkhof castle and the Belvedere Tower. It is not clear whether they had met before.