The Anglo-Saxons lived and ruled in Britain between 1500 and 1,000 years ago.
They were people from north-western Europe (the lands that we now call Denmark, north-western Germany and The Netherlands) who began to invade England while the Romans were still in control, but when their power was weak. That was just over 1500 years ago.
England was ruled by Anglo-Saxons for over 500 years.
The British were the people who lived in Britain when the Romans left.
They had not been allowed to develop fighting skills while the Romans ruled. So, when the Romans left they could not defend themselves against the attacks on their land from the north and west.
They needed help, and they chose to pay the Anglo-Saxons to fight for them against the Irish and the Scots.
The Anglo-Saxons were a warrior people who got much of their wealth by conquering other lands.
They were made of many tribes, but the largest were the Angles, the Saxons and the Jutes.
Anglo-Saxons had raided the shores of Britain even when the Romans were in control. They used small, light boats that could get far up rivers where the Roman galleys could not follow.
At first, the Anglo-Saxons did help to keep the Scots and the Irish at bay. However, their demands for continued help got larger and larger. First it was money, then it was land, and then it was more land.
They also knew how weak the British were and so, after a while, help turned to conquest and more and more Anglo-Saxons arrived from Europe to stake out and claim land for themselves. This was the beginning of Anglo-Saxon England.