Julius Caesar's invasions of Britain in the context of "Commentarii de Bello Gallico"

Roman Britain was the territory that became the Roman province of Britannia after the Roman conquest of Britain, consisting of a large part of the island of Great Britain. The occupation lasted from AD 43 to AD 410.

Britain was invaded by Julius Caesar in 55 and 54 BC as part of the Gallic Wars. According to Caesar, the Britons had been overrun or culturally assimilated by the Belgae during the British Iron Age and had been aiding Caesar's enemies. The Belgae were the only Celtic tribe to cross the sea into Britain, for to all other Celtic tribes this land was unknown. He received tribute, installed the Celtic king Mandubracius over the Trinovantes, and returned to Gaul. Planned invasions under Augustus were called off in 34, 27, and 25 BC. In 40 AD, Caligula assembled 200,000 men at the Channel on the continent, only to have them gather seashells (musculi) according to Suetonius, perhaps as a symbolic gesture to proclaim Caligula's victory over the sea. Three years later, Claudius directed four legions to invade Britain and restore the exiled king Verica over the Atrebates. The Romans defeated the Catuvellauni, and then organized their conquests as the province of Britain. By 47 AD, the Romans held the lands southeast of the Fosse Way. Control over Wales was delayed by reverses and the effects of Boudica's uprising, but the Romans expanded steadily northwards.

The Roman conquest of Britain was the Roman Empire's conquest of most of the island of Britain, which was inhabited by the Celtic Britons. It began in earnest in AD 43 under Emperor Claudius, and was largely completed in the southern half of Britain (most of what is now called England and Wales) by AD 87, when the Stanegate was established. The conquered territory became the Roman province of Britannia.

Following Julius Caesar's invasions of Britain in 54 BC, some southern British chiefdoms had become allies of the Romans. The exile of their ally Verica gave the Romans a pretext for invasion. The Roman army was recruited in Italia, Hispania, and Gaul and used the newly-formed fleet Classis Britannica. Under their general Aulus Plautius, the Romans pushed inland from the southeast, defeating the Britons in the Battle of the Medway. By AD 47, the Romans held the lands southeast of the Fosse Way. British resistance was led by the chieftain Caratacus until his defeat in AD 50. The isle of Mona, a stronghold of the druids, was attacked in AD 60. This was interrupted by an uprising led by Boudica, in which the Britons destroyed Camulodunum, Verulamium and Londinium. The Romans put down the rebellion by AD 61.

The Anglo-Saxon Chronicle is a collection of annals in Old English, chronicling the history of the Anglo-Saxons.

The original manuscript of the Chronicle was created late in the ninth century, probably in Wessex, during the reign of King Alfred the Great (r. 871–899). Its content, which incorporated sources now otherwise lost dating from as early as the seventh century, is known as the "Common Stock" of the Chronicle. Multiple copies were made of that one original and then distributed to monasteries across England, where they were updated, partly independently. These manuscripts collectively are known as the Anglo-Saxon Chronicle. Almost all of the material in the Chronicle is in the form of annals, by year. The earliest is dated at 60 BC, the annals' date for Julius Caesar's invasions of Britain. In one case, the Chronicle was still being actively updated in 1154.