The Tribes outside Greek and/or Roman Territories would have commerce with the civilized states and learned to like coinage. When coinage dried up for various reasons, they would strike their own versions. These coins are usually highly stylized. Celtic coins were made in Gaul, Spain, England and north of the Rhine. In Britain, these coins generally date from about 100 BC until the various tribes were conquered by the Romans as late as the middle of the first century AD. The Romans under Julius Caesar first crossed into Britain during his wars in Gaul in 54/55 BC, but he found nothing of interest and deemed Britain not worth conquering. In 43 AD the emperor Claudius personally led the Roman invasion of Britain. The Iceni tribe under the warrior queen Boudicca revolted against Rome in 61 AD.