War (1337–1453) generally fought on opposing sides, with the Scots standing for the French against the English under the Auld Alliance. France in later periods, in turn, often intervened on Scottish soil for the Scots. This French involvement had increasingly complex political consequences for all sides by the later 16th century. The Anglo-Scottish Wars can formally be said to have ended with the Union of the Crowns in 1603, wherein England and Scotland entered a personal union under James VI and I, who inherited both crowns. Bloody conflict between the two states nevertheless continued to arise in different and more complex guise throughout the course of the 17th century. Border wars between Scotland and England During the mid-15th century, there were many conflicts on the border of England and Scotland, most notably the Battle of Sark in 1448. These battles were the result of England's ongoing military campaigning in France and Scottish attempts to support the House of Valois. Flodden campaign England under Henry VIII declared war on France in 1512 (as part of the larger conflict known as the War of the League of Cambrai). James IV of Scotland invaded England in fulfillment of his alliance with France (even though married to Henry's sister Margaret). In 1513, after preliminary raids by borderers came to grief, James's main army invaded England. His artillery quickly subdued English castles such as Norham and Wark. However, James issued a formal challenge for an open field battle to the English army under the Earl of Surrey and then fortified his position; this perceived lack of chivalry led Surrey to warn James that no quarter would be given or accepted. Surrey's army manoeuvred around the Scottish army, which launched an attack to open a route north to Scotland. In the resulting disastrous Battle of Flodden, James IV was killed, along with many of his nobles and gentry, the "Flowers of the Forest". 1514–1523 James V of Scotland was an infant barely a year old at his father's death. Various factions among the Scottish nobles contended for power, and custody of the young king. While Henry VIII secretly encouraged some of them, English armies and some families of English and nominally Scottish Border Reivers repeatedly forayed and looted in southwest Scotland, to maintain pressure on the Scottish authorities. Eventually, after the faction of the Earl of Angus gained control, peaceful relations were restored between England and