Question:  John Stewart, Earl of Mar was the youngest son of an unpopular and ineffective what?

<P0-S0>  James was an unpopular and ineffective monarch owing to an unwillingness to administer justice fairly, a policy of pursuing alliance with the Kingdom of England, and a disastrous relationship with nearly all his extended family. <P0-S1>  However, it was through his marriage to Margaret of Denmark that the Orkney and Shetland islands became Scottish. <P0-S2> James III (10 July 1451/May 1452 – 11 June 1488) was King of Scots from 1460 to 1488. <SEP> <P1-S0> Lord Cardross is a title in the Peerage of Scotland, since 1695 a subsidiary title of the earldom of Buchan. <P1-S1>  It was created in 1606 for John Erskine, 18th Earl of Mar, with remainder to his heirs male and assignees whatsoever and with the power to nominate his successor. <P1-S2>  In 1617 he nominated his second son by his second wife, Henry Erskine, Master of Cardross, to be his successor in the lordship of Cardross. <P1-S3>  The Earl of Mar died in 1634 and was succeeded in the earldom of Mar by his son by his first wife, John, and in the lordship of Cardross by his grandson David Erskine, the second Lord Cardross, the son of Henry, Master of Cardross, who had died in 1628. <P1-S4>  The second Lord was a supporter of The Engagement and was barred from sitting in Parliament in 1649. <P1-S5>  He was succeeded by his eldest son, the third Lord. <P1-S6>  He emigrated to North America to escape religious persecution and established a colony in what is now Carolina. <P1-S7>  His son, the fourth Lord, succeeded his kinsman in the earldom of Buchan in 1695. <P1-S8>  However, it was not until 1698 that his claim was established by the Scottish Parliament. <P1-S9>  For further history of the title, see Earl of Buchan. <SEP> <P2-S0> He was unmarried and was succeeded by his nephew, the fourth Earl. <P2-S1>  He had already been created Baron Leitrim, of Manor Hamilton in the County of Leitrim, in 1783, and Viscount Leitrim in 1793, also in the Peerage of Ireland. <P2-S2>  He was succeeded by his son, the second Earl. <P2-S3>  In 1800 he was elected as one of the 28 original Irish Representative Peers. <P2-S4>  It was created in 1795 for Robert Clements, 1st Viscount Leitrim. <P2-S5>  As Lord Leitrim's two younger brothers had both died unmarried before him the titles became extinct on his death in 1952. <P2-S6>  He also sat as Member of Parliament for County Leitrim. <P2-S7>  Lord Leitrim was the son of the influential politician and financier Nathaniel Clements. <P2-S8>  Lord Leitrim was murdered along with his clerk and driver by three men named Neil Shiels, Michael Mc Elwee and Michael Heragty while on his way to his residence in Milford in 1878. <P2-S9>  He was succeeded by his eldest son, the fifth Earl. <P2-S10>  He served as Lord-Lieutenant of the City of Londonderry. <P2-S11>  Lord Leitrim served in the Royal Navy. <P2-S12>  However, he predeceased his father, unmarried. <P2-S13>  A deeply unpopular landlord,Lord Leitirim was instructed to arm himself for protection and to be in the company of a strong bodyguard. <P2-S14> Earl of Leitrim (pronounced "Leetrim") was a title in the Peerage of Ireland. <SEP> <P3-S0> John Stewart, Earl of Mar (December 1479 – 11 March 1503) was the youngest son of James III of Scotland and Margaret of Denmark.