Fitzalan was a royal ward of King Richard's half-brother John Holland, 1st Duke of Exeter, along with a large part of the Arundel estates.

Eventually, Fitzalan escaped from his guardian and joined his uncle Thomas Arundel, the deposed Archbishop of Canterbury, in exile.

Early the next year a group of Barons who had been close to the deposed King Richard II revolted—known as the Epiphany Rising—amongst them Fitzalan's former guardian John Holland.

In 1405 there was a revolt in the north of England, led by Richard le Scrope, Archbishop of York; and Thomas de Mowbray, 4th Earl of Norfolk.

This apparently led to a falling out between Fitzalan and his uncle, Archbishop Thomas Arundel, who objected to the execution of a fellow prelate.

The King announced his intention that a fleet would be sailing to Calais, and issued instructions to ambassadors to go to Burgundy's offer of a military aid against Orleans.

The very next day the peace was renewed by the French nobility in a promissory letter to Henry IV signed by the dukes of Berry, Orleans, Bourbon and Burgundy.

On 10 August 1412, the peace was again threatened by Thomas, Duke of Clarence who extorted a humiliating ransom from the Armagnacs after he had landed at St Vaast-le-Hogue.

One of the king's close friends he displayed the cardinal virtues of loyalty to the Lancastrian monarchy, as well as enjoying the honour of personal comradeship.

[3]} The new King Henry V restored the Earl of Arundel to a place of influence, immediately appointing him Lord Treasurer, as well as constable of Dover Castle and Warden of the Cinque Ports.

On 19 March 1415, The Lord Warden was ordered to summon and array seamen for forthcoming fleet operations: 57 ships from the Cinque Ports in 40 days were expected to assemble.

The following day 24 April, the king rewarded his friend with an additional £300 on top of a modest salary as Lord Treasurer of £100 per annum.

When it was revealed the earl of March was inveigled into the Southampton Plot, Arundel and Lord Scrope provided the bulk of the 10,000 marks fine imposed by Henry for this illegal marriage to Anne Stafford.

Bishop Richard Countenay of Norwich had died, the Duke of Clarence was ill, but Arundel remained the King's "great friend".

The Southampton plotters attempted to implicate Arundel, but as their testimony unravelled it became clear Sir Thomas Gray was speaking spiteful lies, and the young earl was held to be without blame.

He had pledged a vow to pray to St John of Bridlington when he was a servant of Prince Hal; and now at Mary Gate, Arundel, a chapel was to be built dedicated to the Virgin.