In the late 1680s, Archibald Pitcairne and David Gregory became devotees of Newton's natural philosophy. In the next decade, they formed the nexus of a scientific circle composed of their students. These men emerge as a specific group from the wider circle of Newton's followers for several reasons, having to do with kinship and community relationships as well as with shared intellectual beliefs. Gregory and, through him, Pitcairne were among the first to recognize Newton's achievement in the Principia. From their base in Edinburgh, later extending to Oxford and Leiden, they inspired several young men, including John and James Keill, John Freind, George Cheyne, George Hepburn, and William Cockburn. Gregory has long been recognized as a central figure among Newtonians, in part owing to his copious memoranda, but Pitcairne's significance both as an intellectual and as a catalyst has been neglected by historians. When one focuses on Gregory and Pitcairne and their notebooks and correspondence, as well as their published works, a well-defined group emerges around them who shared several characteristics. Politically, they were Tories. In religion, they were High Church Anglicans who valued the episcopacy and those points of ritual and doctrine that distinguished the English church from nonconformity. With the exception of John Freind, these men were Scots and shared kinship ties as well as geographic origin in the east and northeast of Scotland. Finally, all the members of this group were at least nominally physicians. Only one of them, John Keill, probably did not practice medicine, but he too took a medical degree.