Grosnez Castle - History

History

The castle was built around 1330 on the orders of Sir John des Roches. The walls were built from the local granite and are thickest on the landward side. Its position on a clifftop 200 ft (~ 60 m) above the sea means that on three sides it is protected by the natural features of the site. A ditch dug into the rock provides protection on the fourth side.

The gatehouse, which is the only substantial remnant today, was protected by a drawbridge and portcullis and would have been very difficult to capture. The castle, though, had a number of weaknesses. There were no sally ports for counter-attacks; there were only two simple buildings providing accommodation; most importantly, there was no water well inside the walls.

The remains of ruined walls, mostly footings, are still present.

The castle was twice captured by the French, in 1373 and 1381 and was probably demolished around the time of the French occupation of Jersey (1461–1468). Certainly, in 1483 the Seigneur of St Ouen was allowed to fortify his manor house and it is unlikely he would have been given permission if Grosnez was still in use.

In 1806, a naval signal station was established at Grosnez to send messages to Guernsey.