It is the second largest of the Channel Islands, an island group roughly north of Saint-Malo and west of the Cotentin Peninsula. The jurisdiction consists of ten parishes on the island of Guernsey, three other inhabited islands (Herm, Jethou and Lihou), and many small islets and rocks.
It is not part of the United Kingdom, although defense and some aspects of international relations are managed by the UK. Although the bailiwicks of Jersey and Guernsey are often referred to collectively as the Channel Islands, the “Channel Islands” are not a constitutional or political unit. Jersey has a separate relationship to the Crown from the other Crown dependencies of Guernsey and the Isle of Man, although all are held by the monarch of the United Kingdom.
The island has a mixed British-Norman culture, although British cultural influence is stronger, with English being the main language and the Pound sterling its primary currency. The island has a traditional local language known as Guernésiais.
Around 6000 BC, rising seas created the English Channel and separated the Norman promontories that became the bailiwicks of Guernsey and Jersey from continental Europe. Neolithic farmers then settled on its coast and built the dolmens and menhirs found in the islands today, providing evidence of human presence dating back to around 5000 BC.
Evidence of Roman settlements on the island, and the discovery of amphorae from the Herculaneum area and Spain, show evidence of an intricate trading network with regional and long distance trade. Buildings found in La Plaiderie, St Peter Port dating from 100–400 AD appear to be warehouses. The earliest evidence of shipping was the discovery of a wreck of a ship in St Peter Port harbour, which has been named “Asterix”. It is thought to be a 3rd-century Roman cargo vessel and was probably at anchor or grounded when a fire broke out. Travelling from the Kingdom of Gwent, Saint Sampson, later the abbot of Dol in Brittany, is credited with the introduction of Christianity to Guernsey.
In 933, the Cotentin Peninsula including Avranchin which included the islands, were placed by the French King Ranulf under the control of William I. The island of Guernsey and the other Channel Islands represent the last remnants of the medieval Duchy of Normandy. In 1204, when King John lost the continental portion of the Duchy to Philip II of France, the islands remained part of the kingdom of England. The islands were then recognized by the 1259 Treaty of Paris as part of Henry III‘s territories.
During the Middle Ages, the island was a haven for pirates that would use the “lamping technique” to ground ships close to the island. This intensified during the Hundred Years War, when, starting in 1339, the island was occupied by the Capetians on several occasions. The Guernsey Militia was first mentioned as operational in 1331 and would help defend the island for a further 600 years.
In 1372, the island was invaded by Aragonese mercenaries under the command of Owain Lawgoch (remembered as Yvon de Galles), who was in the pay of the French king. Owain and his dark-haired mercenaries were later absorbed into Guernsey legend as invading fairies from across the sea.
Early modern period:
As part of the peace between England and France, Pope Sixtus IV issued in 1483 a Papal bull granting the Privilege of Neutrality, by which the Islands, their harbors and seas, as far as the eye can see, were considered neutral territory. Anyone molesting Islanders would be excommunicated. A Royal Charter in 1548 confirmed the neutrality. The French attempted to invade Jersey a year later in 1549 but were defeated by the militia. The neutrality lasted another century, until William III of England abolished the privilege due to privateering activity against Dutch ships.