Cherbourg-Octeville is a subprefecture located at the northern end of the Cotentin peninsula in the northwestern French department of Manche officially formed when the commune of Cherbourg absorbed Octeville on 28 February 2000. Formerly a communein its own right, it was merged into the new commune of Cherbourg-en-Cotentin on 1 January 2016.
Cherbourg-en-Cotentin is protected by Cherbourg Harbour, between La Hague and Val de Saire, and the city has been a strategic position over the centuries, disputed between the English and French. Cited as one of the "keys to the kingdom" by Vauban, it became, by colossal maritime development work, a first-rate military port under the leadership of Napoleon I, and holds an arsenal of the French Navy. A stopping point for prestigious transatlantic liners in the first half of the 20th century, Cherbourg was the primary goal of US troops during the invasion of Normandy in 1944.
Along with its use as a military, fishing and yachting port, it is also a cross-Channel ferry port, with routes to the English ports of Poole and Portsmouth, the Irish ports of Rosslare Harbour and Dublin, and St Helier on Jersey.