[8] The siege was fought between 1 October and 19 November 1594 and was conducted by English and French troops against a Spanish fort constructed on the Crozon Peninsula near Brest.

Reports of a Spanish expedition under Juan del Águila hoping to seize the major port of Brest caused greater concern and John Norreys, already in France, wrote a warning letter to the Queen.

Águila's chief engineer, Captain Cristóbal de Rojas, designed a modern fortification, christened El Leon - companies took turns in construction, foraging, and defence.

Spanish admiral Pedro de Zubiaur arrived with twelve ships landing equipment, which accelerated the construction of the fort, and two shaped bastions with a glacis were formed in front of the drawbridge guarding where the peninsula joined the mainland.

It had turned out several huge barrels of gunpowder blew up in one of the main French siege batteries (either ignited by accident or by a stray Spanish shot) killing or wounding many.

Aumont received news of Águila's relief force and ordered the besiegers to double their efforts, in particular putting pressure on the miners to complete the mining for detonation and to launch an immediate assault.

[20] On 17 November the mine was complete and promptly blown, causing huge damage to the fort's wall and killing and injuring around fifty of the garrison.

Three large assaults were made by the columns and there was desperate fighting in the breach; a cannonball killed Paredes whilst leading his troops in defence.

After bitter fighting the attacks were called off as there were fears and rumours that Águila had arrived with his relief force - among the many casualties from the breach was Frobisher, who was carried away.

[9] During the evening word got through to the garrison of Águila's approach and there was much hope for victory particularly after the repulse of the attack but the Spanish had very little ammunition and only one officer was left alive unwounded.

[4][20] When news of the fort's fall reached him, Águila, who was only a few miles away, led a hasty retreat, leaving behind his heavy baggage and artillery in order to escape a feared trap.

The prisoners were then released and sent back to Águila; Aumont had praised their bravery in the defence in the letters he gave and themselves told the news of the final storming and the subsequent massacre.

[23] The Spanish retention of Blavet allowed for a spoiling attack on Cornwall the following year but this was only a minor descent that proved that England's defences were found wanting.

[11] The defeat effectively ended their hopes to use Brest as a launching point for an invasion of England and gave Philip II a further blow to his naval aspirations.

[10] The French king Henry IV in this opportunist moment then declared war on Spain on 17 January 1595 which would last until the Peace of Vervins, signed three years later.