Over 1,100 years before William the Conqueror became the King of England after the Battle of Hastings, Julius Caesar came, saw, and conquered part of "Britannia," setting up a Roman province with a puppet king in 54 BCE. In the new province, the Romans eventually constructed a military outpost overlooking a bridge across the River Thames. The new outpost was named Londinium, and it covered just over two dozen acres. By the 2nd century CE, Londinium was a large Roman city, with tens of thousands of inhabitants using villas, palaces, a forum, temples, and baths. The Roman governor ruled from the city in a basilica that served as the seat of government. What was once a 30 acre outpost now spanned 300 acres and was home to nearly 15,000 people, including Roman soldiers, officials and foreign merchants. The Romans also built heavy defenses for the city, constructing several forts and the massive London Wall, parts of which are still scattered across the city today. Ancient Roman remains continue to dot London's landscape today, reminding everyone that almost a millennium before it became the home of royalty, London was already a center of power.

Shortly after Emperor Hadrian came to power in the early 2nd century CE, he decided to seal off Scotland from Roman Britain with an ambitious wall stretching from sea to sea. To accomplish this, the wall had to be built from the mouth of the River Tyne - where Newcastle stands today - 80 Roman miles (76 miles or 122 kilometers) west to Bowness-on-Solway. The sheer scale of Hadrian's Wall still impresses people today, but as the Western Roman Empire collapsed in the late 5th century, Hadrian's Wall was abandoned and Roman control of the area broke down.

Little is known of this period of British history, but soon the Anglo-Saxons - who had been harassing the Saxon Shore as pirates - showed up and began to settle the land, creating a patchwork of little kingdoms and starting a new era of British history. Several early medieval historians said the Anglo-Saxons were invited to Britain to defend the region from the northern tribes and ended up taking over.

However they came to control most of England, the Anglo-Saxons became the dominant power in the region for nearly 500 years, and the strength of their cultural influence could be felt even after William the Conqueror won the Battle of Hastings and became the first Norman ruler on the island. The efforts to consolidate his rule in England were complicated from the start, both due to external enemies and those jockeying for his position while he was still alive, but the Normans would manage just barely to cling to power over England, and William remains the last foreign conqueror of the island.

The Jutes are overlooked among the early inhabitants of Britain, though not for any lack of accomplishments or influence on their part. The Jutes first came to England in a wave of migration with the Angles and Saxons in the 5th century and established one of the earliest Germanic kingdoms on the island. The Jutes also played a major role in Britain's adoption of Christianity and the island's evolution from one of many warring tribes and kingdoms to being a unified kingdom that provided the foundation for the medieval and modern British nation-state. In fact, the Jutes were so closely related to the Angles and Saxons that the nature of their existence has been, and continues to be, the subject of scholarly debates. Although historians and archaeologists have identified a Germanic tribe known as the Jutes that migrated to England at the same time as the Angles and Saxons, the attempt to distinguish them from the other tribes has been questioned. Some scholars believe they were a legitimately unique tribe, while others think they were a coalition of people who migrated, fought against other tribes, and sometimes combined and coalesced with other tribes to establish an evolving ethnic identity.