The name of David Hume first emerges in the 1580s and receives sporadic mention thereafter, giving the impression that he played only a minor role in the politics of the period in which he lived. That was certainly not the case. On the contrary, his significance was considerable. Sadly, there is a great dearth of documentary evidence. The exact dates of his birth and death, for example, are unknown. This thesis is an attempt to piece together as much as possible of his life and to show how significant he was in influencing events in the troubled period of James's minority. Rejoicing in the Union of the Crowns and its potential for a united Britain, Hume describes himself as 'Scoto Britannus'. That designation fully represents his awareness, not only of the political realities of a united Britain but his strong sense of a Scottish and British heritage and beyond that of the great classical tradition of which he was both inheritor and expositor. First and foremost, however, he was a Scot. Hume's importance was to become clearer with the role he took in the continuing debate on bishops and their place in James's religious scheme of things. From that he emerged as a most articulate spokesman of the presbyterian cause, though it is significant that he was not a churchman, and his influence on that cause continued after his death.