It was fought on 14 June 1646 off the Spanish-ruled town of Orbetello, on the coast of Tuscany, Italy, between a French fleet led by Admiral Armand de Maillé, Marquis of Brézé, and a Spanish fleet commanded by Miguel de Noronha, 4th Count of Linhares sent to break the blockade of Orbetello and relieve the town, besieged since 12 May by a French army under the command of Prince Thomas of Savoy.

[4][5] After a hard but inconclusive fight during which Admiral Brézé was killed, the French fleet withdrew to Toulon leaving the sea to the Spanish,[6] who decided not to pursue them to relieve Orbetello.

Made of 36 galleons, 20 galleys, and a large complement of minor vessels, it had on board an army of some 8,000 infantry and 800 cavalry with baggage under the command of Thomas Francis of Savoy, who had previously been in the employ of the Spanish Crown.

The isthmus was occupied thanks to a battery mounted aboard the French galleys, and soon the lagoon was filled with armed boats gathered by Jean-Paul de Saumeur, Chevalier Paul.

[10] Linhares' second in command was Admiral General Francisco Díaz de Pimienta, who displeased by his always secondary role, had recently resigned, claiming ill health.

[15] At dawn on June 14 the Spanish fleet bore down off the Giglio Island in a line astern with the galleons and the galleys at the forefront and 8 lagging vessels closing the formation.

[1] Admiral Brézé formed his fleet in a line shortly after, alternating galleons and galleys, and sailed westward in a gentle breeze, closed with Linhares' ships.

[2] The foremost Spanish galleons Testa de Oro, León Rojo, and Caballo marino received heavy damage, while a French fireship blew up.

Forty men were killed or wounded aboard the French fleet[17] One of them was Admiral Brézé, cut in half by a cannonball which hit the stern of his flagship Grand Saint Louis.

[7] Comte du Daugnon, Brézé's successor, decided to set sail to Porto Ercole to make repairs instead of pursuing the Spanish fleet, which had sought refuge behind the Giglio island.

[20] Two days later several Dunkirkers were dispatched to force the Talamone's port mouth, and 8 ships arrived from Naples at Porto Santo Stefano, destroying or capturing about 70 tartanes and barges which contained the supplies of Thomas of Savoy's army during the operation.

[20] The siege was not lifted until an army under the Duke of Arcos and the Marquis of Torrecuso stormed the besieger camp a month later, killing or capturing over 7,000 men and taking all the artillery and the baggage, which turned the whole French campaign into a failure.

[8][21] Dissatisfied with the outcome of the naval battle, Philip IV, who expected that the French fleet would have been destroyed, and the honour of his navy restored,[21] dismissed and imprisoned Count of Linhares and Admiral Pimienta, among other officers, accusing them of mismanagement and abandonment of their forces.