The etymology of the name "Bern" is uncertain. According to the local legend, based on folk etymology, Berchtold V, Duke of Zähringen, the founder of the city of Bern, vowed to name the city after the first animal he met on the hunt, and this turned out to be a bear. It has long been considered likely that the city was named after the Italian city of Verona, which at the time was known as ''Bern'' in Middle High German. The city was sometimes referred to as ''Bern im Üechtland'' to distinguish it from Verona. As a result of the finding of the Bern zinc tablet in the 1980s, it is now more common to assume that the city was named after a pre-existing toponym of Celtic origin, possibly ''*berna'' "cleft". The bear was the heraldic animal of the seal and coat of arms of Bern from at least the 1220s. The earliest reference to the keeping of live bears in the ''Bärengraben'' dates to the 1440s.