Can you check the following sentences for me? Let me know how I can improve them, please.

1) England was invaded by some Germanic tribes, known under the name of (?) the Anglo-Saxons, then by the Vikings, who were defecate by the Normans.
2) As far as religion s concerned (?), Christianity retreated into the western parts of the country.
In the sixth century the monk Augustine was sent by Pope Gregory I the Great to convert the Anglo-Saxons to Christianity.
3) Under the Norman rule (?) society was organised according to a feudal system. (or a feudal system was adopted)
4) In 409 AD the Romans left the island, that was then invaded by the Anglo-Saxons, then (??) by the Vikings and finally by the Normans.
5) Try to start your sentences with the subject rather than with a local complement (??): in medieval society the Church played a fundamental role. Better: the Church played a fundamental role in …..
6) Three languages were spoken in England during the Middle Ages: French by the aristocracy ( or: French was used by the aristocracy), Anglo-Saxon by the people and Latin by the Church.

Read carefully to find all the corrections:

1) England was invaded by some Germanic tribes, known as Anglo-Saxons, then by the Vikings, who were defeated by the Normans.

2) As far as religion is concerned, Christianity retreated into the western parts of the country. In the sixth century, the monk Augustine was sent by Pope Gregory I the Great to convert the Anglo-Saxons to Christianity.

3) Under Norman rule, society was feudal.

4) In 409 AD, the Romans left the island, which was then invaded by the Anglo-Saxons, then by the Vikings, and finally by the Normans.

5) The Church played a fundamental role in ...

6) Three languages were spoken in England during the Middle Ages: French by the aristocracy, Anglo-Saxon by the common people, and Latin by Churchmen.

1) England was invaded by Germanic tribes known as the Anglo-Saxons, followed by the Vikings, and eventually conquered by the Normans.

Improvement: Consider rephrasing it for clarity. For example, "England witnessed invasions by various Germanic tribes, specifically the Anglo-Saxons, followed by subsequent invasions by the Vikings, culminating in the Norman Conquest."

2) When it comes to religion, Christianity gradually retreated to the western regions of the country. In the sixth century, Pope Gregory I sent the monk Augustine with the objective of converting the Anglo-Saxons to Christianity.
Improvement: Restructure the sentences for better flow. For example, "Christianity gradually receded towards the western parts of the country in terms of its influence. In the sixth century, Pope Gregory I dispatched the monk Augustine with the mission of converting the Anglo-Saxons to Christianity."

3) Under Norman rule, a feudal system was adopted to organize society.
Improvement: The sentence is already well-structured and straightforward.

4) In 409 AD, the Romans departed from the island, and subsequently, it experienced invasions by the Anglo-Saxons, then the Vikings, and finally the Normans.
Improvement: Rephrase the sentence for better clarity. For example, "In 409 AD, after the Romans left the island, England faced successive invasions by the Anglo-Saxons, followed by the Vikings, and ultimately conquered by the Normans."

5) It is recommended to begin your sentences with the subject instead of a locational complement. For instance, "In medieval society, the Church played a crucial role."
Improvement: The suggestion provided already puts the subject first, improving the sentence structure.

6) During the Middle Ages, three languages were spoken in England: French was used by the aristocracy, Anglo-Saxon by the common people, and Latin by the Church.
Improvement: The sentence is already well-structured and clear.