Max Adams tells his readers very early on that ‘the real Dark Age in British history can be found in Book I of Bede’s Ecclesiastical History’. It is this lacuna, the period between 580 and 710, that his new work on Oswald Iding, king of Northumbria, is intended to fill. It would not be right to call the book a biography; the paucity of sources for the first centuries of Anglo-Saxon England makes it almost impossible to construct anything like full lives of its earliest kings. Instead, Adams has created a narrative of seventh-century Britain in which his hero occupies a central role and around the thread of whose life are hung fascinating detail, analysis and speculation on almost every aspect of the country’s political, religious and cultural life.

Therein lie both the book’s great strengths and its principal weakness. Adams shines a spotlight on the career of the man who, after a reign of a mere eight years from 634 to 642, became one of the first Christian martyrs in England, killed at the hands of Penda, the