On 18 July 1545, a French invasion force of between 150 and 250 ships approached the coast of the Isle of Wight. Mariners, gunners and soldiers formed a force of around 50,000 men commanded by Admiral Claude d’Annebault. Both England and France had been preparing for this engagement since Henry VIII's successful siege of Boulogne in September of the previous year. To Francis I, the ousting of the English from Boulogne was essential not only for his kingdom's defence but also for national pride. By launching an attack on English territory, Francis hoped to coerce the Boulogne garrison into retreat.

With the navy of the English crown at its greatest size for over a century, the Tudor king did not halt, but instead continued to build new warships in the royal dockyards while waiting for the appearance of his rival's sea forces. Sightings and rumours soon circulated across the Channel of vessels being equipped for war in Marseille, Brittany and Dieppe. Meanwhile, in the Italian Provinces, French commissioners were recruiting mercenary ships and their crews to support an invasion of England. The English regime responded by also seeking the recruitment of armed Italian bands.

Previous clashes in the living memories of Henry and Francis had shown that naval warfare was in its infancy and often led to disastrous results. In August 1512, two of the largest warships in the English and French fleets had clashed at St Mathieu. The Regent and la Cordelière, using traditional medieval tactics, met their doom as Regent grappled and boarded the Breton vessel, only for a fire to break out on la Cordeliére that quickly spread to the connected English ship, decimating both, along with their crews. Naval warfare continued to adopt the boarding-and-close-combat tactic, and in April of the following year, disaster would strike again when the English Admiral Edward Howard died in a failed attempt to board a French galley in the Channel.

Thirty-two years later, the English and French rivalry was revived in the Solent for what would be the most heavily armed sixteenth-century sea conflict between the two powers.