It was hoped to join up with two English forces in the vicinity of the River Loire, but by early September the Anglo-Gascons were facing the much larger French royal army on their own.

In the event the French succeeded in cutting off the Prince's army, but then decided to attack it in its prepared defensive position anyway, partly from fear it might slip away, but mostly as a question of honour.

During this both sides compromised and the Treaty of Brétigny was agreed by which vast areas of France were ceded to England, to be personally ruled by the Black Prince, and John was ransomed for three million gold écu.

[8] In 1345 and 1346 Henry, Earl of Lancaster, led a series of successful campaigns in Aquitaine and the combined English and Gascon forces, or Anglo-Gascons, were able to push the focus of the fighting away from the heart of Gascony.

[20][21] In April 1355 Edward and his council, with the treasury in an unusually favourable financial position, decided to launch offensives that year in both northern France and Gascony.

[22][23] John attempted to strongly garrison his northern towns and fortifications against the expected descent by Edward III, at the same time as assembling a field army; he was unable to, largely because of lack of money.

On 5 April 1356 John arrested the notoriously treacherous Charles II, king of Navarre, one of the largest landholders in France[46][note 3] and another nine of his more outspoken critics; four were summarily executed.

The French army had inherent weaknesses: it consisted of thousands of very small contingents; unaccustomed to cooperating with each other; unknown to their commanders; and of variable health, training and equipment.

The Black Prince called a grand assembly of the Gascon nobility and representatives of the towns, made a show of seeking their advice and when it appeared there was a consensus for war asked for funds with which to prosecute it.

[63] The gathering point for the Anglo-Gascon army was Bergerac; the town had good river supply links to Bordeaux[64] and from there the Prince could strike in several directions.

On 14 August the Anglo-Gascon army crossed the River Vienne,[71] halting on the 15th at Lesterps to rest and repair equipment, having marched 113 miles (182 km) from Bergerac.

[73][71] The modern historian David Green has described the progress of the Black Prince's army as "deliberately destructive, extremely brutal ... methodical and sophisticated.

Some time around 20 August he offered the garrison of Breteuil free passage to the Cotentin, a huge bribe, and permission to take their valuables and goods, which persuaded them to vacate the town.

[79] The Anglo-Gascons had been advancing in the general direction of Bourges, a large and well-fortified town where the Count of Poitiers had moved his army from Languedoc and was rallying regional French forces.

Poitiers retreated as the Anglo-Gascons advanced on Bourges, and a division of the Black Prince's army tried and failed to take the town, then burnt the suburbs and continued north.

John sent home nearly all of the infantry contingents, leaving an entirely mounted force which had the mobility and speed to match that of the Black Prince's all-mounted army.

Disbanding the large number of infantry units also reduced the French wage bill, and John was convinced the utility of many of the poorly trained and equipped militia was low.

Early on 8 September the Black Prince's army reached Tours, where he received news that Lancaster was not far to the east, on the other side of the Loire, and hoped to join him soon.

Being shallow-draught vessels propelled by banks of oars the galleys could penetrate shallow harbours and were highly manoeuvrable, making them effective for raiding and ship-to-ship combat in meeting engagements.

The troops gathered were split up to guard the coast and the ships sailing to Southampton to transport the army were ordered to remain in port until the galleys had left.

[94] As for the Black Prince, the unusual height of the river[87] and the French control of the bridges, meant Lancaster was unable to cross and effect a junction.

Meanwhile the Black Prince did not wish to rapidly retreat to the safety of Gascony, but to manoeuvre in the vicinity of the French army so as to persuade it to attack on unfavourable terms, without himself becoming cut off.

Hearing of this, and losing hope that Lancaster would be able to join him,[98] the Black Prince moved his army some 8 miles (13 km) south to Montbazon where he took up a fresh defensive position on 12 September.

[99] The same day John's son and heir Charles, the Dauphin, entered Tours, having travelled from Normandy with 1,000 men-at-arms,[100] and Hélie de Talleyrand-Périgord, Cardinal of Périgord arrived at the Black Prince's camp to attempt to negotiate a two-day truce on behalf of Pope Innocent VI.

[99][101] Happy to do battle, but concerned that a two-day delay would leave his army with its back to the Loire in an area with few supplies, the Black Prince dismissed Talleyrand and marching hard crossed the River Creuse at La Haye on the 13th, 25 miles (40 km) to the south.

The Black Prince saw an opportunity to attack the French while they were on the march, or possibly even while crossing the Vienne, and so set off at first light on the 17th to intercept them, leaving his baggage train behind to follow on as best it could.

Many Anglo-Gascons pursued the remaining, fleeing, French, although the Black Prince held back most of his army, not wishing to scatter it in the close vicinity of the enemy, and camped at Savigny-Lévescault.

He was persuaded to discuss terms after Talleyrand pointed out that the two armies were now so close that if the French declined to attack, the Anglo-Gascons would find it almost impossible to withdraw.

[111][112] The French discussed these proposals at length, with John in favour, but several senior advisers felt it would be humiliating to, as they saw it, have at their mercy the Anglo-Gascon army which had devastated so much of France and to tamely allow it to escape.

[143] By the Treaty of Brétigny vast areas of France were ceded to England, to be personally ruled by the Black Prince, and John was ransomed for three million gold écu.