In the fifth century, Paulinus of Nola in Campania, Italy, is said to have been the first to install bells on a church. As a result, campanology began as the study of bell ringing. By approximately AD 930, bell towers with bells were widespread in most churches in Britain. These towers provided warnings about fires or other disasters, and also served as landmarks for travelers. Until the 13th century, most churches had only one bell, but by then people wanted more than one sound to warn them of danger. So, between 1220 and 1250, Henry III ordered that two large bells be hung in every parish church in England. The king's bellman was appointed by the bishop to lead these teams of men who worked closely with local masons. They built many churches, but also public buildings such as town halls, libraries, and court houses. The team leader usually took an apprentice who would go on to become a bellfounder too. In time, these men came to be known as "bellmen." The word "campana" means "small bell" in Latin, so campanology refers to the study of small bells. Bells are used in many cultures around the world to announce the start and end of services, to mark the passing of time, and to notify the community of emergencies such as fires or floods.