Referendums are familiar events across the modern political landscape, from Brexit in 2016 to the same-sex marriage postal ballot in Australia in 2017. Across the European Union controversial issues have faced the voters in Hungary, Italy and Turkey. Often these votes resulted in spectacular defeats for the ruling parties and have prompted the resignations of both David Cameron and Mateo Renzi. At other times, as in the cases of Vladimir Putin and Abdel Fattah el-Sisi, such referendums serve to bolster their governments. This book asks why governments risk their position in the face of uncertain odds and whether referendums strengthen or weaken democracy. Covering the history of referendums since the Middle Ages, this book explains why politicians submit issues to the people and why they sometimes miscalculate the outcome. Government by referendum questions if referendums, far from being a populist device (and contrary to popular belief), have actually performed the function of a democratic constitutional safeguard.