Shakespeare's Richard II, first published almost 200 years after Richard's death in 1400, opens with Thomas Mowbray, earl of Nottingham and duke of Norfolk (c. 1367–99) challenging Henry Bolingbroke, earl of Hereford (1367–1413), to a duel. This key event in Richard's downfall, which took place between two of his most powerful nobles, happened in 1398. Bolingbroke would depose his cousin Richard the next year to become King Henry IV. While Shakespeare was writing a play loosely based on historical events, his vivid opening of the play with Mowbray throwing down the gauntlet and challenging Bolingbroke to a duel captures the tension and importance of such an event in the later Middle Ages.

And, as discussed in Chapter 1, the ‘Victorious and Vanquished’ was ideally placed to predict the outcome of a duel or battle since it pitted two values against each other. As in the case of Eleanor Cobham, discussed Chapter 6, onomancies could be used to predict when someone might die in a general sense, years in the future, rather than a sick person on their deathbed. These reasons for prediction are far more sinister than medical use by a physician in a critical situation, and far outside the realm of medical practice. But for these reasons, among others, a wide array of prognostics, including onomantic devices, were owned by and appealed to the higher ranks of medieval society – the gentry and nobility – who jostled for power and influence – and royalty.

This chapter will first examine the manuscript evidence for the ownership of onomantic devices in gentry circles. It will then move on to deal with the manuscript evidence for onomancy as an item for the aristocracy – to predict the outcome of a duel – looking at a particular version of the ‘Sphere’ that circulated in the later part of the fifteenth century.