King James vows to fight his way to London. Queen Margaret tries to prevent him, and Lord Thomas Howard supports her. James vows to punish them when he returns -- but he never returns; the English slay him and twelve thousand men at Flodden
King James IV was unusually long-lived for a Stewart king; he lived all the way to forty (1473-1513). But it wasn't for lack of trying; he twice went to war with England. The first attempt, in support of Perkin Warbeck, was in 1502, and accomplished nothing.
To cement the post-1502 peace, James IV married Margaret Tudor, the elder daughter of England's King Henry VII. (This was the marriage that eventually brought the Stewarts to the throne of England.) But that didn't prevent his warmongering. In 1513, the new English king Henry VIII was away in a sort of a mock campaign against France. James decided to go to war.
Unfortunately for James, the defense of the border was in the hands of Thomas Howard, then Earl of Surrey (1443-1524). Surrey was the son of John Howard, Richard III's Duke of Norfolk, and had fought for Richard III at Bosworth. But with Richard dead, Howard was given a partial pardon (being given the Surrey earldom though not the Norfolk dukedom). This may have been because, with Richard and the elder Howard dead, Surrey was the best soldier in England.
However that may be, Surrey gathered an army to meet the invading Scots. The two forces are believed to have been about equal in size, but Surrey outmaneuvered the Scots and inflicted a crushing defeat, killing James, the cream of his army, and about a third of his troops -- a defeat which came to be commemorated in the popular lament "The Flowers o' the forest.". Surrey lost perhaps 5%-10% of his own men.
Scotland -- as always when a new monarch came to the throne -- was plunged into chaos. The border was safe for many years. Surrey received the Norfolk dukedon, which has remained in the Howard family ever since. - RBW