 He died in 1663 and was succeeded by his son, Robert Makgill, second Viscount Oxfuird.Robert Makgill, second Viscount Oxfuird had a son named Thomas who died in 1701, five years before his father, Robert and left no issue.William Maitland son of Christian Makgill, daughter of the second viscount then claimed the viscountcy but this was challenged in 1734 by James Makgill of Nether-Rankeillor who was sixth in descent from Lord Rankeillor.