His father died when John Hastings was around one year old, and he became a ward of King Edward III while remaining in his mother's care.

The latter were compounded by his apparent inability to work alongside the famed soldier Sir John Chandos, who, although head of the King's forces there, was far below Pembroke in rank.

John Hastings was born on 29 August 1347 at Sutton Valence Castle, Kent and baptised that day in the local church, St Mary the Virgin.

[3] Laurence Hastings died a year to the day after his son's birth,[4] and John remained in the care of his mother,[2] while becoming a ward of the King, Edward III (r. 1327–1377).

As Anne was a cousin of Pembroke's first wife a papal dispensation was sought for this marriage and received from the Archbishop of Canterbury on 1 July 1368.

[2] Much of Pembroke's adult life was devoted to royal service, beginning in October 1364 when he was in attendance on King Edward III at Dover.

This effectively created a trust for his heirs, in the event of his death abroad, and if they should also die heirless, the estate would return intact to the King.

[19] Pembroke's first active service came in the same year; he accompanied the King's son, Edmund, Earl of Cambridge, on a much-delayed campaign in Aquitaine in south-west France[20] with a force of 400 men-at-arms.

[21] Pembroke and Cambridge landed at St Malo,[4] apparently escaping the notice of a local French commander,[22] and marched 260 miles (420 km) south to Angoulême, joining the Black Prince there in late April.

[22] Pembroke's force then captured Bourdeilles castle after an eleven-week siege[4] when a mistimed sortie allowed the English entry.

[4] [26] In revenge, says Cokayne, Pembroke then raided Anjou again, before being despatched with Cambridge to relieve Belleperche,[29] in early 1370, where they raised the French siege.

[31] Pembroke was embarrassed at being rescued by Chandos and this "did nothing to abate the ill-feeling between the two leaders" and "was a serious blow to Edward III's attempts to stabilize Aquitaine", according to the historian R. I.

[4] A contemporary chronicler reported that the French King, Charles V, when he heard of Chandos's death, said that no-one was now "left able to make peace between England and France".

He took the stall of the deceased Thomas, Earl of Warwick;[4] the renewal of war, however, meant that he was rarely able to attend Garter feasts again.

[34] While the King was willing to devote much of his personal wealth to this campaign, he was less keen to allow large numbers of English knights to join them.

[35] Gaunt was accompanied by Walter, Baron Mauny, one of his closest advisers and Pembroke's father-in-law, who had become frustrated at dictating strategy from a distance.

[2] It is possible his role was not purely administrative, as some contemporary chronicles portray him as the main leader of a parliamentary faction which politically attacked the King's clerical ministers.

[39] Sumption suggests the immediate cause for Pembroke's attack was his recent experiences in "frustrating and underfunded campaigns" while, at home, as the writer of a contemporary French tract colourfully put it, "the clergy reposed peacefully beneath shady canopies elegantly scoffing fat delicacies".

[44][note 4] Ruthin attempted to make peace with Pembroke, even coming to him at Yardley Hastings in the company of the Earls of Hereford, March and Salisbury.

[61] The plan appears to have been for Pembroke to land at La Rochelle, giving succour to Poitou and the Saintonge,[62] and then, having strengthened Aquitaine, to march northwards, cross the Loire, and join up with the King, who would also be on campaign.

[63] Unknown to the English, Charles V became aware of Pembroke's pending invasion of Aquitaine shortly after Edward III's Great Council had decided upon it.

Attempting to enter the harbour, Pembroke encountered a much larger force of twelve large Castilian galleys[4] [note 8] and eight carracks.

[65] Pembroke was unable to replicate the English victories of such earlier naval battles as Winchelsea and Nájera because of his lack of archers, which would otherwise have allowed him to lay down suppressing fire on the enemy crews.

[78] Around this point – with horses running wild and kicking holes in the hulls[36] and his men throwing themselves overboard to avoid the flames – Pembroke surrendered.

A fellow prisoner, Sir John Trailly, following his return to England, reported Pembroke's reaction to a parson connected to the Grey affinity.

To finance this du Guesclin had to sell his Spanish lordships of Soria[2] and Molina, which he had previously captured from Spain,[4] back to the Castilian King.

[88] The first instalment was eventually lodged in a short-term moneylending account[89] for du Guesclin, with a Fleming in Bruges, by which time Pembroke was ill.

[2][note 10] Ormrod suggests that news of his death was greeted with "genuine shock" by the English nobility, both on account of Pembroke's youth and aristocratic status.

When John the younger died childless, "the son of that Reynold Grey whom the second Earl had disliked so heartily claimed the heirship-general",[85] and the inheritance was broken up.

The truth, Jack says, is that "Pembroke was luckless and arrogant, but not necessarily incompetent",[4] while Ormrod argues that he was not so close to the King as to be completely uncritical of policy.