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Castle Cornet


How old is Castle Cornet?

About 800 years old.  The earliest parts of the castle date from the 13th century (1200s).  At that time, Guernsey was part of the duchy of Normandy.  For more information on life in those days, go to Norman Guernsey.   

Why was it built?

To defend St Peter Port harbour.  Guernsey's deep and sheltered harbour has been an important and safe place to stop for more than a thousand years.  

What was there before the Castle?

There was just an isolated rock, about a mile off Guernsey and surrounded by sea.  

Castle Cornet was an island? When was it attached to Guernsey?

Yes that's correct.  The Castle and Guernsey were joined in the 1860s by a wooden bridge.  This was done as part of extensions to the harbour. The bridge was replaced with the concrete structure seen today following the Second World War.

Where does the Cornet name come from?

There are two main suggestions:

1.  The name relates to the shape of the structure.  

2.  The name relates to a, now lost, family name.

The island on which the castle stands appears to have been known as Cornet islet and so the castle takes its name from that.  The Cornet  family are mentioned as being present at the dedication of the town church in 1312.

What castle features does it have?

Lots - including a portcullis, battlements and towers.  At the end of this page, you will find 'Medieval CC tour' and accompanying notes.  There are examples of castle features within these documents.  

Where is the oldest part of the Castle?

We believe that the original medieval castle started with a square tower at the south end.  This was known as the 'Tour Carrée'.  

Are there any dungeons?

We have no evidence of dungeons in the castle.  The castle has been used a prison during its history.  

Did important people live there?

Yes.  The Governors of Guernsey (the Crown's representative) lived in the castle for many years.  The last Governor to live there was Sir Christopher Hatton.  He left after lightning struck the tower in 1672 and caused an enormous explosion.  Governors of Guernsey since then have always lived in Guernsey.

Why is there a noon day gun?

Today is it fired as a spectacle to enjoy but it did have practical uses in the past.  When soldiers lived in the castle, a shot was fired at noon and 9.30pm each day.  The noon firing marked lunch and the evening firing marked curfew when the soldiers must return to their barracks.  For more information go to our page about the noon day gun.  



The History of Castle Cornet by Guernsey Museums & Galleries 

Guernsey's Medieval Castles by Gregory Stevens Cox


  • Castle Cornet Aerial View from Breakwater
  • Noon-Day Gun Firing