[5] The siege was fought between the French Royal army under Marshal D'Aumont reinforced by an English contingent under Sir John Norreys who besieged the town of Morlaix, which was held by the combined forces of Spain and the Catholic League of France.

[7] Aguila marched his troops and were close to linking up with Mercour's force but their relief column ran into segments of the detached English.

Aguila thought he was up against a much larger force - the Spaniards believed that they totalled 6,000 men but didn't realise that the English was a mere detachment.

Aguila fearing being overwhelmed then decided to withdraw his men to Blavet on September 17, which meant that Mercour could not relieve the castle of Morlaix.

[7] Soon matters of the garrison turned for the worse when they spotted an English fleet under Sir Martin Frobisher carrying the siege train of heavy guns for Norreys.

The fort was taken in a brutal assault which cost the entire garrison but also nearly a quarter of the besieging force which included Martin Frobisher and denied the Spanish a major base there.