What drove the Vikings' wanderlust?

Dr Cat Jarman has penned a new book about the Vikings, after being inspired when she discovered a small orange bead found in a mass grave in Derbyshire had come from India. https://www.dailymail.co.uk/home/books/article-9403625/What-drove-Vikings-wanderlust.html?ns_mchannel=rss&ns_campaign=1490&ito=1490