The Corieltauvi were a largely agricultural people who had few strongly defended sites or signs of centralised government. They appear to have been a federation of smaller, self-governing tribal groups. From the beginning of the 1st century, they began to produce inscribed coins: almost all featured two names, and one series had three, suggesting they had multiple rulers. The names on the earliest coins are so abbreviated as to be unidentifiable. Later coins feature the name of Volisios, apparently the paramount king of the region, together with names of three presumed sub-kings, Dumnocoveros, Dumnovellaunus and Cartivelios, in three series minted ca. 45 AD. The Corieltauvi had an important mint, and possibly a tribal centre, at Sleaford.