On 7th November, 1809, Napoleon's troops entered Hostalric with the aim of taking the town since it was on the only natural pass between Girona and Barcelona. Once the village had been razed, the Castle became the main target. On 13th May 1810, after five months of siege and with the walls demolished and the water supply cut off, the French managed to occupy the fortress.

This episode from the Peninsular War has left its mark on the current appearance of Hostalric Castle. This fortress was built in 1716 by the Engineer General of Philip V, George Prosper Verboom, who was also responsible for the Citadel in Barcelona and the fortification of La Seu Vella in Lleida. It was designed to take account of the new fortification models by the military engineer, Vauban. It had three bastions, defence towers, a moat and two ravelins.

The structure that has lasted up to the present day is formed by the underground entrance, cart gateway, the guards’ section, the bastion of Santa Tecla, the second gateway, the main arsenal, the crenellated bastion, the main gate, the parade ground, the clock tower and the road to the town.
Almost nothing remains of the original construction from the medieval period, which was demolished by the Duke of Noailles in 1695. Only the fortified road which ran from the town to the castle is of late medieval origin. The two walls parallel to the road were protected by two circular towers, of which only a small stretch is preserved.