The island of Jersey and the other Channel Islands represent the last remnants of the medievalDuchy of Normandy that held sway in both France and England. Jersey lies in the Bay of Mont Saint-Michel and is the largest of the Channel Islands. It has enjoyed self-government since the division of the Duchy of Normandy in 1204.

The earliest evidence of human activity in Jersey dates to about 250,000 years ago (before Jersey became an island) when bands of nomadic hunters used the caves at La Cotte de St Brelade as a base for hunting mammoth.

Evidence of occupation and wealth has been discovered in the form of hoards. In 1889, during construction of a house in Saint Helier, a 746-g gold torc of Irish origin was unearthed. A Bronze Age hoard consisting of 110 implements, mostly spears and swords, was discovered in Saint Lawrence in 1976 - probably a smith's stock. Hoards of coins were discovered at La Marquanderie, in Saint Brelade, Le Câtel, in Trinity, and Le Câtillon, in Grouville (1957).

In June 2012, two metal detectorists announced that they had uncovered what could be Europe's largest hoard of Iron Age Celtic coins, which may be worth up to £10 M, after a search spanning 30 years. The extracted mass including soil and the hoard reportedly weighed about three-quarters of a tonne, and could contain up to 50,000 Roman and Celtic coins. This came after an earlier find of 60 Celtic coins, in the same area, by the same men. Hoards of coins may have been buried in the island so as to protect them from Julius Caesar's armies which were advancing through France.

In October 2012, another metal detectorist reported a new Bronze Age find, the Trinity Hoard.

The island took the name Jersey as a result of Viking activity in the area between the 9th and 10th centuries.

From 1204 onwards, the Channel Islands ceased to be a peaceful backwater and became a potential flashpoint on the international stage between England and France.

In the Treaty of Paris (1259), the King of France gave up claim to the Channel Islands. The claim was based upon his position as feudal overlord of the Duke of Normandy. The King of England gave up claim to mainland Normandy and appointed a Warden, a position now termedLieutenant Governor of Jersey and a Bailiff to govern in his stead. The Channel Islands were never formally absorbed into the Kingdom of England, however.

Mont Orgueil castle was built at this time to serve as a royal fortress and military base. During the Hundred Years' War, the island was attacked many times and was even occupied for a few years in the 1380s.

It was 1348 when the Black Death reached the Island, ravaging the population.

During the 16th century, the islanders adopted the Protestant religion and life became very austere. The increasing use of gunpowder on the battlefield meant that the fortifications on the island had to be adapted and a new fortress built to defend St Aubin's Bay.

During the 1640s, England, Ireland and Scotland were embroiled in the War of the Three Kingdoms. The civil war also divided Jersey, and while the sympathy of islanders lay with Parliament, the de Carterets (see Sir George Carteret and Sir Philippe de Carteret II) held the island for the king.

Methodism arrived in Jersey in 1774, brought by fishermen returning from Newfoundland. Conflict with the authorities ensued when men refused to attend militia drill when that coincided with chapel meetings. The Royal Court attempted to proscribe Methodist meetings, but King George III refused to countenance such interference with liberty of religion.

Two railways, the Jersey Western Railway in 1870, and the Jersey Eastern Railway in 1874, were opened. The western railway from St Helier (Weighbridge) to La Corbièreand the eastern railway from St Helier (Snow Hill) to Gorey Pier. The two railways have never been connected. Buses started running on the island in the 1920s, and the railways could not cope with the competition. The eastern railway closed in 1926 and the western railway in 1936 after a fire disaster that year.

Elementary education became obligatory in 1899, and free in 1907. The years before the First World War saw the foundation of cultural institutions, the Battle of Flowers and the Jersey Eisteddfod. The first aeroplanes arrived in Jersey in 1912.

Following the withdrawal of defences by the British government and German bombardment, Jersey was occupied by German troops between 1940 and 1945. The Channel Islands were the only British soil occupied by German troops in World War II. This period of occupation had about 8,000 islanders evacuated, 1,200 islanders deported to camps in Germany, and over 300 islanders sentenced to the prison and concentration camps of mainland Europe. Twenty died as a result. The islanders endured near-starvation in the winter of 1944-45, after the Channel Islands had been cut off from German-occupied Europe by Allied forces advancing from the Normandy beachheads, avoided only by the arrival of the Red Cross supply ship Vega in December 1944. Liberation Day - 9 May is marked as a public holiday.