In the 16th century, Morlaix was a very prosperous port, the third in Brittany after Nantes and Saint-Malo.
The famous parish enclosures and houses in Pondalez bear witness to this flourishing past. The city derives this wealth mainly from the industry and trade in linen canvases, better known as the "Crees du Léon". It also benefits from a strategic location at the mouth of the English Channel, halfway between Northern and Southern Europe, which allows it to develop a privileged maritime trade with England, Holland and the Iberian countries.
This power excites the lusts and Morlaix is regularly looted. In 1522, when relations between France and England were particularly tense, English sailors ransacked and burned the city. It will take Morlaix 10 years to recover.
Exasperated by these attacks, the inhabitants decided to take charge of their defence by building a fort on the rocky islet of Taurus. The task is difficult, but the obvious strategic benefit is obvious: the only passageway for large ships is to the west of the rock, within gun range…
Work began around 1542. Little is known about this first fort, other than that it has a 6.50 metre enclosure.
Brittany occupies a highly strategic position due to its geographical proximity to England. A position that Louis XIV intends to defend. He also sent his military engineer Vauban to modernize the fortifications on the Breton coast.
The charge of the Château du Taureau was then taken from the inhabitants of Morlaix, and the fort was completely rebuilt, with the exception of the French tower. Objective: to build a stronger and larger fort.
The work will take approximately 45 years to complete. The building, built mainly of granite from the neighbouring island of Callot, has an oblong shape that follows that of the rock. It is 60 metres long, 12 metres wide and 12 metres high for a built area of 1450 m2. There are 11 casemates that can each receive a cannon.
The fort also houses soldiers' and officers' quarters, two dungeons, a canteen and kitchen, a chapel and latrines. As for drinking water, it is provided by a cistern that collects rainwater.
As the port of Morlaix declined, the defence of the Bay was no longer a major strategic issue and the military mission assigned to Château du Taureau became a definitive deterrent.
Also from 1721, even before its complete completion, the fortress was diverted from its original purpose and used as a prison.
The place, lost in the middle of the sea, offers, it is true, a maximum of guarantees in terms of security. Surrounded by a double granite and liquid barrier, the Taurus despairs any attempt to escape. Those who take the risk may face a dire fate, such as the prisoner Sébastien Trévou, who drowned in 1793.
Who are the prisoners? Under the Old Regime, most of the reclusive were Breton aristocrats imprisoned by order of the King by "letters of seal", most often at the request of their own families, anxious to avoid dishonour.
Libertine, a misalliance, madness, an immoderate taste for alcohol or gambling can certainly lead to a forced stay at the Fort du Taurus, in one of the 11 specially equipped cells. Prisoners' living expenses are covered by families who pay a board for food, clothing or laundry. When they do not pay their debt, the prisoner is simply released….
The surveillance of prisoners is entrusted to a company of invalids, composed, depending on the period, of 13 to 60 soldiers at the end of their careers, declared unfit for combat because of their poor health or their old age.