Final answer:
Before the Anglo-Saxon conquest, the Romans called the island 'Britain' or 'Britannia.' After they left in 400 CE, Britain was invaded by the Angles and Saxons, leading to the formation of Anglo-Saxon England.
Step-by-step explanation:
The island in the upper part of the map, before it was conquered by the Anglo-Saxons in the 400s and 500s, was a Roman colony known as Britain.
Before the Anglo-Saxon conquest, the Romans referred to the island as Britannia, which is Latin for Britain. After abandoning the territory around 400 CE, Britain experienced a period of political instability, subsequently leading to invasions by various Germanic tribes, primarily the Angles and Saxons around the late 5th century. These tribes originated from present-day northern Germany and Denmark. Over time, they settled and established multiple kingdoms in England, pushing out Roman culture and traditions. This resulted in a thoroughly de-Romanized society, paving the way for the distinct Anglo-Saxon cultural and linguistic influence that characterized early English history.
This period also set the stage for future dynamics, such as the Norman Conquest at the Battle of Hastings in 1066, which greatly impacted the development of England as a nation.