The Knights Hospitaller were a group of people who provided help and care for sick and injured people during the Middle Ages. They were like a special kind of hospital. They had buildings called hospices, or hostels for the sick, which were run by Hospitallers. These Hospitallers were knights who had taken a special vow to serve the sick and poor. They also provided protection for pilgrims travelling to the Holy Land. The Knights Hospitaller were very important in the Middle Ages and were respected for the good work they did.