Castle Cornet has stood as Guernsey’s grandest military installation for over 800 years, having been constructed between 1206 and 1256.

The castle originally sat on an island known as Castle Rock, almost a kilometre from the shore of St Peter Port (Guernsey’s capital). It was connected to the mainland by a breakwater in 1861, as part of an extensive overhaul of the town’s harbour.

When the French captured Guernsey in 1338, during the Hundred Years’ War, Castle Cornet was besieged and fell to the French. The castle remained in French hands until 1345, almost six years after the rest of the island was liberated.

The Castle successfully defended St. Peter Port from subsequent French attacks in 1372, 1380 and 1461.

The castle was remodelled in the mid-1540s to better host canons, which proved vital in Guernsey’s defence against another attempted French invasion in 1547.

The Castle is perhaps most famous for its role in the English Civil Wars. The Castle supported the Royalist cause, while the rest of Guernsey supported the Parliamentarians.

The Parliamentarians from St. Peter Port besieged the castle from 1642 onwards, meanwhile the Castle bombarded the town with its canons. The castle held out for nine years, aided by their fellow Royalists on the island of Jersey.

In 1651, Parliamentarians from England and Guernsey captured Jersey. The Crown of England, which has been kept in Jersey’s Courthouse, was smuggled to Castle Cornet. In December of that same year, two years after the execution of King Charles I, the Castle finally surrendered, becoming the penultimate royalist garrison in the British Isles to do so. The Crown was returned to London, and eventually destroyed under Cromwell’s government.

In 1672, the castle’s keep was tragically destroyed in a huge powder explosion triggered by a bolt of lightning. Thereafter, the Governor of Guernsey kept his residence in St. Peter Port, not Castle Cornet.

The Castle, like all Guernsey’s fortifications, saw extensive upgrades and renovations during the Napoleonic wars period, and also ceased to be Guernsey’s sole prison in 1811.

During the Second World War, when German forces occupied the Channel Islands, the castle was fitted with a number of concrete modifications and modernisations, although these alterations were relatively minor compared to those made to other fortifications in Guernsey.

The Castle, which had previously been a possession of the British Crown, was given as a gift to the people of Guernsey in 1947, and is now home to 4 museums, a restaurant and several period gardens, and hosts many guided tours, public events and outdoor theatre performances