In March 1389 Arnold, a Gascon by birth, claimed to have been living in Dartmouth for 20 years. He is, however, not mentioned in English records before 1383, when he purchased the freedom of the city of Exeter. After obtaining letters patent of denization he was legally entitled to own real estate in England, and he subsequently acquired property in Dartmouth, where he soon came to occupy a prominent position in the affairs of the town.
Arnold’s links with Gascony suggest that his principal trading concern was with wine, but he also imported the produce of the Mediterranean and of the Iberian peninsula, and found a profitable sideline during the winter months in transporting pilgrims to the shrine of St. James at Compostella. Arnold’s exploits overseas resulted in his appearance as defendant in several lawsuits brought in the courts of chivalry and admiralty. He appealed against judgements made in the constable’s court in 1396 and 1411, having been found guilty of breach of arrest and the spoliation of the goods of a Breton knight; and over a period of ten years he made several appeals to the King’s Council protesting against the sentence imposed on him in the court of admiralty to pay as much as £226 and 170 francs to John Baker of Dartmouth as the purchase price of his ship. Arnold, clearly one of the most able sea-captains of his day, had earlier come to the attention of the government. In June 1398 Richard II gave him permission to take 20 men-at-arms and 40 archers to Portugal to assist João I to crush the revolt of his half-brother; and the first two Lancastrian kings were quick to enlist his services for the safe-keeping of the seas. Le Lythenard, of which he was part-owner, was requisitioned for royal service in 1402, and beginning in that year (incidently also the year that Arnold first secured appointment as a customs official), his seafaring activities are well documented.
During the state of hostilities with France in the early years of Henry IV’s reign, accidental breaches of truces with neighbouring countries were bound to occur. In 1402 Arnold’s ships were party to violent seizures of goods carried in Flemish ships in the Channel, and in July 1403 one of his own vessels, arrested in London, was held until he agreed to abide by the award of the chancellor, Bishop Beaufort of Lincoln, for the restitution of a moiety of Le Petre of Castile, which he had captured at sea. Even so, in the following month he and other seamen of Dartmouth were formally authorized to put to sea to make war on any Bretons discovered breaking the truce and to arm their crews for the defence of merchant shipping. The Channel became unsafe for foreign vessels whatever their flag: in the autumn a fleet from Dartmouth, Bristol and Plymouth under the command of John Hawley I of Dartmouth and Thomas Norton of Bristol took seven Castilian prizes which they then left in Arnold’s custody in the harbour at Dartmouth. Although in March 1404 he was ordered to return the valuable cargoes or else answer before the Council, he neglected to take either course of action. Arnold was involved in a similar way after the seizure of Le Marie Knight of Sluys in 1408, and in the following year he joined with other local men, in defiance of the King’s writ, in harbouring John William I of Kingswear and his crew after they had committed even more serious offences at sea. In 1410 the Council thought it expedient to bind Arnold and John Corp in recognizances of 500 marks to ensure the delivery of a writ to their friend John Hawley II.
In his later years Arnold was faced with personal troubles in the form of quarrels with his stepson, Robert Stamford. In 1415 the latter’s wife brought an action against him in the court of admiralty for detaining ransoms due to a former husband of hers, and Stamford himself alleged in Chancery that when, acting for the King’s searcher, he had boarded one of Arnold’s ships at Dartmouth, his stepfather made a murderous assault on him. But it was the younger man who was outlawed, and in 1417 Arnold, then described as ‘the King’s servant’, was granted all of his movables.
