Henry of Grosmont, 1st Duke of Lancaster

In 1328 Edward III's regents had agreed to the Treaty of Northampton with Robert Bruce, King of Scotland (r. 1306–1329), but this was widely resented in England and commonly known as turpis pax, "the cowards' peace". Some Scots nobles refused to swear fealty to Bruce, and were disinherited. They left Scotland to join forces with Edward Balliol, son of King John I of Scotland (r. 1292–1296),[7] whom Edward I had deposed in 1296.[8] One of these was Grosmont's father-in-law, Henry de Beaumont, Earl of Buchan and veteran campaigner of the First War of Scottish Independence. Robert Bruce died in 1329; his heir was 5-year-old David II (r. 1329–1371). In 1330 Edward III, who had recently assumed his full powers, made a formal request to the Scottish Crown to restore Beaumont's lands which was refused. In 1331 the disinherited Scottish nobles gathered in Yorkshire, and led by Balliol and Beaumont plotted an invasion of Scotland. Edward III was aware of the scheme but turned a blind eye. Balliol's forces sailed for Scotland on 31 July 1332. Five days after landing in Fife, Balliol's force of some 2,000 men met the Scottish army of 12,000–15,000 men and crushed them at the Battle of Dupplin Moor. Balliol was crowned king of Scotland at Scone on 24 September 1332.[8] Balliol's support within Scotland was limited and within six months it had collapsed. He was ambushed by supporters of David II at the Battle of Annan a few months after his coronation and fled to England half-dressed and riding bareback. He appealed to Edward III for assistance.[9][10]

On 10 March Balliol, the disinherited Scottish lords and some English magnates crossed the border and laid siege to the Scottish town of Berwick-upon-Tweed.[11] Six weeks later a large English army under Edward III joined them, bringing the total number of besiegers to nearly 10,000.[12] Grosmont was present at the siege, but it is not known if he marched with his father-in-law and Balliol, or with the main English effort.[13] The Scots felt compelled to attempt to relieve the siege and an army of 20,000 men attacked the English at the Battle of Halidon Hill, 2 miles (3.2 km) from Berwick. Under intense bow-fire the Scottish army broke, the camp followers made off with the horses and the fugitives were pursued by the mounted English knights. The Scottish casualties numbered in thousands, including their commander and five earls dead on the field.[14] Scots who surrendered were killed on Edward's orders and some drowned as they fled into the sea.[15] English casualties were reported as fourteen; some chronicles give a lower figure of seven.[16][17] About a hundred Scots who had been taken prisoner were beheaded the next morning, 20 July.[18] It is presumed that Grosmont took part in the battle, but it is possible that he was part of the detachment posted to ensure that the garrison of Berwick did not sally.[13] Berwick surrendered the day after the battle and Grosmont witnessed and sealed the articles of surrender and, a little later, the town's new charter.[13]

Encouraged by the French King, most Scots refused to accept Balliol as their monarch. In December 1334 Grosmont accompanied Edward III to Roxburgh in Scotland. The English force of 4,000 accompanied little and withdrew in February. Grosmont was a member of Edward III's negotiation team when a brief truce was agreed shortly after at Nottingham. In July Grosmont accompanied Edward III on another invasion of Scotland, with an army of 13,000 – for the time an extremely large force. Scotland was quelled as far as Perth and Grosmont took a senior role in raiding deeper into the country.[19] In 1336 Grosmont was given command of 500 men-at-arms and 1,000 longbowmen and marched to Perth. He was given full plenipotentiary powers by the King. After Edward III reached Perth with the main English army, Grosmont was despatched on a long-range raid to Aberdeen, 80 miles (100 km) away. He returned after two weeks, having razed Aberdeen and devastated the country on the way.[20] Edward went south for six weeks, leaving Grosmont in charge of English-occupied Scotland. Believing that he would soon be at war with France, Edward withdrew most of his forces from Scotland in mid-1336 and sent Grosmont to London to plan the defence of the English Channel ports from the mouth of the Thames westward.[21]

From 1333 Grosmont's father had begun transferring estates into Grosmont's name, giving him an independent income. In 1337 he was one of six men Edward III promoted to the higher levels of the peerage; one of his father's lesser titles, earl of Derby, was bestowed upon him. He was also granted a royal annuity of 1,000 marks[note 2] (£935,900 as of 2020[note 3]) for so long as his father lived, and a number of lucrative estates and perquisites were settled on him.[24][25] During early 1337 Grosmont was again serving in Scotland. By the time he returned to London, war with France had commenced.[note 4]

In 1338 Grosmont travelled with Edward III to Flanders, and to a meeting with Louis IV, Holy Roman Emperor, at Coblenz. This was a diplomatic mission amidst much pageantry; Edward III concluded agreements with a number of rulers, including Louis IV, whereby they would provide troops in exchange for payment and was appointed Imperial vicar. Throughout the year, French naval forces ravaged the English south coast.[28] Edward III planned to invade France with his army of allies in 1339, but was finding it impossible to raise the money to pay them; he and his ambassadors had committed him to far greater expense than the Exchequer could fund. Grosmont led part of Edward III's army when it finally invaded France in September 1339.[29][30] Cambrai was besieged, the area around it devastated, and an unsuccessful attempt made to storm the town. The allied army pressed further into France, but the French refused battle. Then, in mid-October, the French issued a formal challenge to battle. Edward accepted and occupied a strong defensive position at La Capelle which the French declined to attack. Having run out of provisions, money and weather suitable for campaigning, the allied army withdrew and dispersed. Grosmont arrived in Brussels with the army at the end of October, where the campaign was celebrated with a Tournament.[31]

From 29 March to 3 April 1340 Grosmont attended Parliament, where a substantial subsidy was voted to the crown.[32] Meanwhile, encouraged by Edward III, the Flemings, vassals of Philip IV, had revolted during the winter. They joined forces with Edward III's continental allies and launched an April offensive, which failed. A French offensive against these forces commenced on 18 May, meeting with mixed fortunes; Edward's outnumbered allies were desperate for the English army to reinforce them.[33]

Grosmont was present at the great English victory in the naval Battle of Sluys in 1340.[30] Later the same year, he was required to commit himself as hostage in the Low Countries for the king's considerable debts. He remained hostage until the next year and had to pay a large ransom for his own release.[34] On his return he was made the king's lieutenant in the north and stayed at Roxburgh until 1342. The next years he spent in diplomatic negotiations in the Low Countries, Castile and Avignon.[3]

August–November 1345 troop movements

  Derby's advance

  Derby's retreat

  Louis of Poitiers' advance

  Derby's advance to Auberoche

  Derby's return to La Réole

Edward III determined early in 1345 to attack France on three fronts. The Earl of Northampton would lead a small force to Brittany, a slightly larger force would proceed to Gascony under the command of Grosmont, and the main force would accompany Edward to either northern France or Flanders.[35][36][37] Grosmont was appointed the King's Lieutenant in Gascony on 13 March 1345[38] and received a contract to raise a force of 2,000 men in England, and further troops in Gascony itself.[39] The highly detailed contract of indenture had a term of six months from the opening of the campaign in Gascony, with an option for Edward to extend it for a further six months on the same terms.[40] Derby was given a high degree of autonomy, for example his strategic instructions were: "si guerre soit, et a faire le bien q'il poet" (... if there is war, do the best you can ...).[41]

On 9 August 1345 Grosmont arrived in Bordeaux with 500 men-at-arms, 1,500 English and Welsh archers, 500 of them mounted on ponies to increase their mobility,[42] and ancillary and support troops.[43] Rather than continue the cautious war of sieges he was determined to strike directly at the French before they could concentrate their forces.[44] He decided to strike at the French at Bergerac, which had good river supply links to Bordeaux, and would provide the Anglo-Gascon army with a base from which to carry the war to the French[45] and sever communications between French forces north and south of the Dordogne. After eight years of defensive warfare by the Anglo-Gascons, there was no expectation among the French that they might make any offensive moves.[42] Grosmont moved rapidly and took the French army at Bergerac by surprise on 26 August, decisively beating them in a running battle.[46] French casualties were heavy, many being killed or captured.[47] Derby's share of the ransoms and the loot was estimated at £34,000 (£33,000,000 in 2020 terms[note 5]), approximately four times the annual income from his lands.[note 6][49]

Grosmont left a large garrison in the town and moved north with 6,000–8,000 men[50] to Périgueux, the provincial capital of Périgord,[51] which Grosmont blockaded, taking several strongholds on the main routes into the city. John, Duke of Normandy, the son and heir of Philip VI, gathered an army reportedly numbering over 20,000 and manoeuvred in the area. In early October a very large detachment relieved the city and drove off Grosmont's force and started besieging the English-held strongpoints.[52] A French force of 7,000 besieged the castle of Auberoche, 9 miles (14 km) east of Périgueux.[53] A messenger got through to Grosmont, who was already returning to the area with a scratch force of 1,200 English and Gascon soldiers: 400 men-at-arms and 800 mounted archers.[54]

After a night march Grosmont attacked the French camp on 21 October while they were at dinner, taking them by surprise. There was a protracted hand-to-hand struggle, which ended when the commander of the small English garrison in the castle sortied and fell upon the rear of the French. They broke and fled. Derby's mounted men-at-arms pursued them relentlessly. French casualties are uncertain, but were heavy. They are described by modern historians as "appalling",[55] "extremely high",[51] "staggering",[56] and "heavy".[53] Many French nobles were taken prisoner; lower ranking men were, as was customary,[57] put to the sword. The ransoms alone made a fortune for many of the soldiers in Grosmont's army, as well as Grosmont himself, who was said to have made at least £50,000 (£49,000,000 in 2020 terms) from the day's captives.[58]

Map of route of Lancaster's chevauchée of 1346

John, Duke of Normandy, the son and heir of Philip VI, was placed in charge of all French forces in southwest France, as he had been the previous autumn. In March 1346 a French army under Duke John, numbering between 15,000 and 20,000,[59] enormously superior to any force the Anglo-Gascons could field,[60] marched on the town of Aiguillon, which commanded the junction of the Rivers Garonne and Lot, meaning it was not possible to sustain an offensive further into Gascony unless the town was taken, and besieged it on 1 April.[59] On 2 April an arrière-ban, a formal call to arms for all able-bodied males, was announced for southern France.[59][61] Grosmont, now known as Lancaster after the death of his father,[note 7] sent an urgent appeal for help to Edward.[62] Edward was not only morally obliged to succour his vassal, but also contractually required to; his indenture with Lancaster stated that if Lancaster were attacked by overwhelming numbers, then Edward "shall rescue him in one way or another".[63]

The garrison, some 900 men, sortied repeatedly to interrupt the French operations, while Lancaster concentrated the main Anglo-Gascon force at La Réole, some 30 miles (48 km) away, as a threat. Duke John was never able to fully blockade the town, and found that his own supply lines were seriously harassed. On one occasion Grosmont used his main force to escort a large supply train into the town.

In July the main English army landed in northern France and moved towards Paris. Philip VI repeatedly ordered his son, Duke John, to break off the siege and bring his army north. Duke John, considering it a matter of honour, refused. By August, the French supply system had broken down, there was a dysentery epidemic in their camp, desertion was rife and Philip VI's orders were becoming imperious. On 20 August the French abandoned the siege and their camp and marched away. Six days later the main French army was decisively beaten in the Battle of Crécy with very heavy losses. Two weeks after this defeat, Duke John's army joined the French survivors. Meanwhile, the English laid siege to the port of Calais.

Philip vacillated: on the day the siege of Calais began he disbanded most of his army, to save money and convinced that Edward had finished his chevauchée and would proceed to Flanders and ship his army home. On or shortly after 7 September, Duke John made contact with Philip, having shortly before disbanded his own army. On 9 September Philip announced that the army would reassemble at Compiègne on 1 October, an impossibly short interval, and then march to the relief of Calais.[64] Among other consequences, this equivocation allowed Grosmont in the south west to launch offensives into Quercy and the Bazadais; and himself lead a chevauchée 160 miles (260 km) north through Saintonge, Aunis and Poitou, capturing numerous towns, castles and smaller fortified places and storming the rich city of Poitiers. These offensives completely disrupted the French defences and shifted the focus of the fighting from the heart of Gascony to 60 miles (97 km) or more beyond its borders.[65][66][67] Few French troops had arrived at Compiègne by 1 October and as Philip and his court waited for the numbers to swell, news of Lancaster's conquests came in. Believing that Lancaster was heading for Paris, the French changed the assembly point for any men not already committed to Compiègne to Orléans, and reinforced them with some of those already mustered, to block this. After Lancaster turned south to head back to Gascony, those Frenchmen already at or heading towards Orléans were redirected to Compiègne; French planning collapsed into chaos.[68]

Coats of Arms of Edmund Crouchback, Earl of Lancaster, and his successors

In 1345, while Grosmont was in France, his father died. The younger Henry was now Earl of Lancaster – the wealthiest and most powerful peer of the realm. After participating in the Siege of Calais in 1347, the king honoured Lancaster by including him as a founding member and the second Knight of the Order of the Garter in 1348.[69][70] In the same year Alice de Lacy died and her life holdings (which she had retained after Thomas of Lancaster was executed), including the Honour of Bolingbroke and Bolingbroke Castle, passed to Grosmont. A few years later, in 1351, Edward bestowed an even greater honour on Lancaster when he created him Duke of Lancaster. The title of duke was of relatively new origin in England; only one other English ducal title existed previously.[note 8]

In addition to this, the dukedom was given palatinate powers over the county of Lancashire, which entitled him to administer it virtually independently of the crown.[71] This grant was quite exceptional in English history; only two other counties palatine existed: Durham, which was an ancient episcopal palatinate, and Chester, which was held by the crown.

It is a sign of Edward's high regard for Lancaster that he bestowed such extensive privileges on him. The two men were second cousins through their great-grandfather King Henry III and practically coeval (Edward was born in 1312), so it is natural to assume that a strong sense of camaraderie existed between them. Another factor that might have influenced the king's decision was the fact that Henry had no male heir, so the grant was made for the Earl's lifetime only, and not intended to be hereditary.[3]

Lancaster spent the 1350s intermittently campaigning and negotiating peace treaties with the French. In 1350 he was present at the naval victory at Battle of Les Espagnols sur Mer (Winchelsea), where he allegedly saved the lives of the Black Prince and John of Gaunt,[72] sons of Edward III. The years 1351–1352 he spent on crusade in Prussia. It was here that a quarrel with Otto, Duke of Brunswick, almost led to a duel between the two men, narrowly averted by the intervention of King John II of France.[73] In the later half of the decade campaigning in France resumed. After a chevauchée in Normandy in 1356 and the Siege of Rennes (1356–57), Lancaster participated in the last great offensive of the first phase of the Hundred Years' War: the Rheims campaign of 1359–1360. Then he was appointed principal negotiator for the Treaty of Brétigny, where the English achieved very favourable terms.[3]

By the time he died in 1361 Henry had participated in 15 military missions, leading 6 of them; been the King's lieutenant 7 times; led 6 significant embassies; and taken part in 12 truce conferences.[74]