This book presents the text of a draft Constitution for an independent Republic of Northumbria. With the North-South divide widening, and 'Levelling Up' failing to deliver, this book accompanies the draft constitutional text with a short introductory essay considering whether there is a case for a more radical option: an independent Northern English state. Responding to the creation of the Northern Independence Party in 2020, this book starts by taking the case for an independent Northumbrian state seriously. In the midst of debates about the future of England, the English regions, and the United Kingdom, it envisages - in the form of a draft constitutional text - an alternative polity for the North, free from Westminster rule. While an independent Northumbrian Republic might seem far-fetched - and indeed, it is not necessarily endorsed as a viable option - the real value of this book is as a constitutional thought experiment. It shows what a radically reformed, democratic, republican constitution might look like. It therefore has a resonance beyond Northern England.