The English invasion of Scotland in August 1400 was the first military campaign undertaken by Henry IV of England after deposing the previous king, his cousinRichard II. Henry IV urgently wanted to defend the Anglo-Scottish border, and to overcome his predecessor's legacy of failed military campaigns. A successful campaign against the Scots would also heighten his own image as a strong ruler and reinforce the new regime.

A large army was assembled slowly and marched into Scotland. Henry was aided by divisions within the Scottish nobility, and won over George, Earl of March, who renounced his allegiance to Robert III of Scotland. However, once in Scotland, Henry's army remained camped near Leith (northeast of Edinburgh) where it could maintain contact with its supply fleet. No pitched battle was ever attempted, nor did the King besiege Scotland's capital, Edinburgh or its Castle. Henry's army left at the end of August after only a brief stay. The campaign ultimately accomplished little except to deplete further the Crown's coffers, and was criticised by contemporary chroniclers. Modern historians have also found little to commend the expedition. It was the last time an English king led an army into Scotland.

Background

War between England and Scotland had started under King Edward I. By the 1370s, cross-border raids and fighting had become the norm in Anglo-Scottish relations. This generally involved Scottish incursions over the border and English attempts to repel them. The last years of Richard II's reign had seen several truces between the countries. However, the 1399 , in which he was deposed by his cousin, Henry Bolingbroke, Earl of Derby, presented the Scots with the opportunity to regain land between the River Tweed and the Solway Firth. As the medievalist Chris Given-Wilson puts it, "England's confusion was Scotland's opportunity", and in May 1399—on Henry's coronation day—Wark Castle, in Northumberland was destroyed by one such Scottish raid. The damage inflicted and the ransoms imposed amounted to over ; another raid in the west reached as far south as Penrith, Cumbria. So Henry's invasion had its roots in the earliest period of the reign, and became entwined in the formation of the new regime: the latest truce with Scotland had expired on the same day Richard abdicated the throne.

Something of a tradition had by then been established, of newly-crowned kings of England launching military campaigns at the beginning of their reigns. Edward III had done so in the first year of his reign and then again on the commencement of his personal rule in 1327 and 1332, respectively. Richard II invaded Scotland immediately on reaching his majority, and Henry V was to do so within three years of acceding to the crown. The historian Anne Curry and colleagues argue that these campaigns were "enforcing... royal will and testing loyalty towards a newly established regime" as well as obtaining material strategic goals. They also instilled national unity following the upheaval caused by Richard's deposition. The presence of Henry IV's sons, Henry of Monmouth and Thomas, alongside him on the campaign was also to be heavy with significance. Curry explain:

In his proclamations, Henry emphasised his own Scottish ancestry as well as the claim to the Scottish throne advanced by Edward I in the 13th century. This, suggests Given-Wilson, might indicate that "whether or not he truly believed that he could unite Britain under his kingship, Henry was not insensible to the possibilities which history presented".

Planning

Although Henry probably preferred to maintain peaceful relations with Scotland, much of the English nobility were keen on a pre-emptive strike. In particular, the Percys— the Earl of Northumberland and his son Henry Percy (known as Hotspur)—who were Wardens of the East and West March, saw a Scottish war as an opportunity for their own aggrandisement. A successful invasion would both provide an opportunity for plunder and protect the northern flank of their estates, which experienced constant raiding. Indeed, some contemporaries believed that the invasion was actually "conceived on the advice and at the instigation of" the Percys, as the Parliament Roll put it. The King felt forced to deny this, in person, to the House of Lords during the November 1399 parliament. The historian A. L. Brown suggests that this indicates the keen interest the King took: as his own personal plan, "it meant a lot to him, and that it had met with criticism", to which he felt obliged to respond vigorously. It was in his interest to show that he was no man's puppet. The House of Commons, however, petitioned Henry not to go north, asking that he stay "in the middle of the realm" and send others if necessary. The King ignored them and pledged to fulfil this vow before God. At around the same time, Henry received a letter from King Robert III of Scotland, which referred to Henry as "Duke of Lancaster, Earl of Derby and Lord High Steward" rather than King of England. This refusal to acknowledge Henry's claim to the throne was a direct personal insult, and probably fuelled his enthusiasm for a Scottish war.

Scottish divisions Probably as persuasive to Henry and his lords were the visible divisions within the Scottish nobility. By April 1398, King Robert faced severe criticism in many parts of his kingdom. Suffering from periodic bouts of illness, he was accused of failing to maintain order. At a general council held at Perth in January 1399, Robert had been forced to surrender power to David, Duke of Rothesay, his son and heir, who was appointed regent.

George Dunbar, Earl of March felt that he had been betrayed by Rothesay's uncle, Robert Stewart, Duke of Albany, over the proposed marriage of Dunbar's daughter to Rothesay. The marriage never came to pass, even though Dunbar and the lady had been living together sometime. Rothesay married Mary Douglas, the daughter of Dunbar's rival on the march, Archibald, Earl of Douglas. Dunbar, jilted and his honour "", appealed to Henry for assistance. Dunbar complained that he had been

Already known as "one of the finest soldiers of his age [and] until now an implacable enemy" of England, says Given-Wilson, Henry sent him a gift of in December. Two months later, Dunbar travelled to London and pledged allegiance to Henry. In Scotland, his estates and properties were seized by the Crown.

Dunbar's involvement was important because, not only was he a major figure in Scottish politics in his own right, but he also had extensive experience in northern warfare. His secession forced the Scottish government to adopt a more conciliatory approach; a letter of 14 March addressed Henry as "our dear cousin of England". Dunbar was a power in eastern Scotland. In the west, Henry found another ally in Donald of Islay, Lord of the Isles. Both Donald and his brother John had been bitter enemies of the Dukes of Rothesay and Albany since the latter pair had led a punitive raid into Donald and John's Lochaber and Islay estates in 1398.

Composition and logistics The English army was not raised through feudal obligation—as Richard II had unsuccessfully attempted in 1385—or the more recent bastard feudal mechanism of indenture. Instead, the King called upon not only his closest tenants-in-chief, but anyone in receipt of royal patronage. Henry's father, John of Gaunt, Duke of Lancaster, had been the richest man in the kingdom after the king, and also possessed the largest retinue. Henry's accession had therefore merged the two largest affinities in the kingdom into a socially and geographically broad-based , or personal retinue. This gave Henry more potential patronage than previous monarchs; this was the basis for his army in 1400. It has been estimated at around 13,000 men—1,771 men-at-arms and 11,314 archers—of which 800 men-at-arms and 2000 archers came directly from the Royal Household. These were, for example, the retinues of John Norbury, the Lord High Treasurer, Thomas Tutbury, Keeper of the Wardrobe and Robert Litton, its controller. Comprising over 230 retinues, this army was "one of the largest raised in late medieval England", say Curry While it was smaller than the massive army assembled in 1345 (that which fought Crécy), it was larger than most mustered for French service. "Only the 1385 campaign to Scotland can compare", argue Curry , at around 13,764 soldiers. Henry's force was larger than Edward III's French army in 1359 (around 10,000 strong), while that of Henry V's Agincourt campaign in 1415 was between 10,000 and 12,000 men. Later in the century, Edward IV's army which invaded France in 1475 amounted to 11,451 men. Only the campaigns of 1346 and 1347 saw armies greater than 12,000 men.

The English nobility had a historic martial duty to follow the King into war. Seven of the eleven adult earls and dukes of England attended, and Henry's sons both brought small forces. The largest contingent was Westmorland's, although 1,000 of his 1,200 men were archers. The army's social composition was broader than that of its predecessor, in part because the recent Epiphany Rising had thinned the number of peers the King could call upon, and many knights were required to stay south and guard against Ricardian-inspired revanchism. Participation was encouraged by a veiled threat to withdraw patronage (for example, annuities) for those who failed to attend. Also joining the campaign was Archambaud, Count of Périgord, who had been deposed from his French titles the previous year and was now living in English exile, along with the picaresque Gascon (and "minor chivalric celebrity", says his biographer, Simon Walker) Jenico Dartasso. Henry commanded an experienced army; many knights and senior captains had served in Ireland under Richard II in the 1390s or with Henry's father in France and Spain; several Household men had served with Henry in Lithuania on his 1390 crusade—as part of the Lithuanian Civil War—fighting at the Siege of Vilnius. Some men's military pedigrees went back to Edward III's 1369 campaign. For wages, men-at-arms received one shilling a day and archers half that, while captains and leaders do not appear to have been paid a higher rate.

While the army attacked on land, the English fleet patrolled the east coast of Scotland, both to blockade Scottish trade and to resupply the army when required. At least three naval convoys were sent from London and the Humber, the first of which delivered of flour and of sea salt to Newcastle upon Tyne, Lindisfarne and Berwick for revictualling the army. One of these convoys comprised 20 ships from the Cinque Ports. Smaller armed convoys sailed from East Anglia, for instance, from Orwell, but details of this provisioning are now unknown; privateers from King's Lynn acted in a protective role. Five barges from the King's own personal fleet also transported goods, food and cash.

Campaign

Approaching Scotland Although Henry had announced the planned invasion at the October 1399 parliament, he did not intend a winter campaign. Instead, he continued to hold quasi-negotiations "in which he must have felt the Scots were profoundly irritating", says Brown, as the Scottish delegation avoided substantive discussion in favour of arguing about the meeting place. No progress was made. The Commons remained wary of a forthcoming war, and, since extravagance had been a major complaint against Henry's predecessor, Henry was probably constrained in requesting a parliamentary subsidy, or tax. In fact, Parliament seems to have considered a possible French invasion the most pressing issue. However, Scottish prevarication during the negotiations ("or rather manoeuvres", comments Brown) confirmed Henry's view that only an armed campaign would bring long-term peace to the border, and he began appointing commissions of array and even sending spies over the border.