The Latin for lead is plumbum. In medieval times, anyone who worked with lead was referred to as a plumber; this can be seen from an extract about workmen fixing a roof in Westminster Palace; they were referred to as plumbers: "To Gilbert de Westminster, plumber, working about the roof of the pantry of the little hall, covering it with lead, and about various defects in the roof of the little hall".[6] Thus a person with expertise in working with lead was first known as a Plumbarius which was later shortened to plumber.