Why did they build motte baily castle?

Motte-and-bailey castles were built primarily for defense and to establish control over a territory. The motte, a raised earthwork mound, provided a vantage point and stronghold, while the bailey, an enclosed courtyard, housed soldiers and livestock. This design allowed for quick construction and effective protection against attacks, making it ideal during the early medieval period when threats from rival factions were common. Additionally, these castles symbolized power and authority for the lords who built them.