How could the crusades change a serfs' life? they could now own land, they could leave the manor, they could have protection by the manor lord, they could build their own homes?

They could now own land

Explanation:

During the Middle Ages, Feudalism was the predominant economic system in Europe. According to this system, serfs were bound to the Feudal Lord, the owner of the land, who gave parts of his land to the serfs so they could till the earth in exchange of a portion of their production. Peasants were not allowed to own land. All this started to change with the Crusades. The crusades weakened the feudal lords; many lost their lives or were left in the East; others became impoverished by the sale of their lands; in addition, the prolonged absence prevented them from monitoring their rights. The kings seized the vacant fiefs and tenaciously reduced the privileges of the lords. For their part, serfs and vassals reached their freedom in exchange for money. Therefore, many peasants were able to buy and own a piece of land. Also, there were peasants who went to the Crusades in the Holy Land and there they became rich men and won their right to buy and own lands.

britian is way too advanced for me my good luck

probally   a few days after there called