In the 15th century the Equestrian Order of the Holy Sepulchre of Jerusalem built a fortress on Meda Gran.
They eventually left and pirate attacks in the 16th century damaged the fortress.
The fortress became a prison during the 18th century and at the time of the Napoleonic Wars was again fortified.

On 29 August 1811 General Joaquín Ibáñez Cuevas y de Valonga, Baron de Eroles, at the behest of Luis Roberto de Lacy and with the assistance of HMS Cambrian, a Colonel Green, and British troops, landed, captured, and destroyed the fort the French had built on Meda Gran.
Green then ordered the fort abandoned.
Several weeks later, on 11 September, de Lacy landed on the island.
He rebuilt, garrisoned and fortified the fort, and symbolically renamed the islands the Isles of the Restoration.
The last military garrison left in 1890.
In the 15th century the Equestrian Order of the Holy Sepulchre of Jerusalem built a fortress on Meda Gran. They eventually left and pirate attacks in the 16th century damaged the fortress. The fortress became a prison during the 18th century and at the time of the Napoleonic Wars was again fortified.
On 29 August 1811 General Joaquín Ibáñez Cuevas y de Valonga, Baron de Eroles, at the behest of Luis Roberto de Lacy and with the assistance of HMS Cambrian, a Colonel Green, and British troops, landed, captured, and destroyed the fort the French had built on Meda Gran. Green then ordered the fort abandoned. Several weeks later, on 11 September, de Lacy landed on the island. He rebuilt, garrisoned and fortified the fort, and symbolically renamed the islands the Isles of the Restoration. The last military garrison left in 1890.
Medes Islands