They had a staff of clerks, who knew how to read, write and keep accounts. When they were away from their castles, lords sent instructions on by letter.
The castle's defense was very important. The lords kept a staff of loyal followers even during peacetime.
Religion played an important part in people's lives in the Middle Ages. Here is the Bishop, wearing a mitre and carrying a crosier. Lords and ladies spent generously on building beautiful chapels in their castles.