I left out a few more sentences I wrote on castles. I need a synonym for "ways, way" and a revision of sentence 2. Thank you very much.

1) Castles came to Britain with the Norman-French invaders. Indeed, castles were a key part of their way of controlling new territories.
2) David first came into contact with the Norman-French ways (I need a synonym) when he went to England when his sister Matilda married the Norman King of England, Henry I (on occasion of his sister's marriage to..?).
3) He ended up staying in England for ten years. When he returned to Scotland, he had a Norman wife, a Norman education and English lands with Norman knights.
4) The Norman way of holding lands was this: the king gave his lords land in exchange for military service. These lords in turn gave part of their lands to other military men, knights, also in exchange for lands.
5) The king and all his lords and knights controlled their lands by means of castles. When David came back to S he also brought feudalism. He had castles all over Scotland because he never stayed in one place.
6) The castles also served as the centres of regional units of government called the shires.

Synonyms for "castle" --

http://thesaurus.com/browse/castle

http://www.castles.org/

Norman-French ways/traditions/lifestyles/mannerisms

2. David?? -- "... went to England after his sister..."

3. comma needed

4. Capital letter after colon when it's a complete sentence following.

ways, customs, ideas

David first came into contact with Norman-French customs when he went to England for his sister's wedding. Matilda married the Norman king of England, Henry I.

1) Castles came to Britain with the Norman-French invaders. Indeed, castles were a crucial part of their method of controlling new territories.

2) David first came into contact with the Norman-French practices when he went to England for his sister Matilda's marriage to the Norman King of England, Henry I.

3) He ended up staying in England for ten years. Upon his return to Scotland, he acquired a Norman wife, received a Norman education, and obtained English lands with Norman knights.

4) The Norman method of holding lands was as follows: the king granted his lords land in exchange for military service. These lords, in turn, allocated some of their lands to other military men, knights, in exchange for land.

5) The king, along with all his lords and knights, controlled their lands through the use of castles. When David returned to Scotland, he brought with him the system of feudalism, resulting in the construction of castles throughout Scotland due to his frequent travels.

6) Additionally, the castles also served as the focal points of regional administrative units known as the shires.