In 1564 Artus de Cossé-Brissac, bishop of Coutances in Normandy, was a member of a French diplomatic mission to Queen Elizabeth. He took the opportunity to assert a claim to exercise episcopal jurisdiction in the Channel Islands. The claim was less preposterous than it might appear, since Coutances's jurisdiction in the islands had been acknowledged throughout Henry viii's reign, and again in that of Mary. Queen and Privy Council took the 1564 claim seriously enough to demand a response from the islanders. After a good deal of prevarication on their part, the crown eventually ruled against the bishop's claim, on the grounds, as argued by the islanders, that they were subject to the bishop of Winchester. In the event, Winchester was not to enjoy its newly rediscovered rights for long. The islands were already in the process of establishing their own churches, using French Calvinist forms of worship and a fully synodical system of church government. From 1576 the islanders governed themselves without reference to episcopal authority, which was not to be re-established, in Jersey, until the reign of James i, and in Guernsey that of Charles ii. When challenged the islanders defended their position by claiming that they were indeed part of the diocese of Coutances, and that they were following the best practice of the reformed churches in that diocese.

This story is well established in outline, largely through the labours of island historians, but above all through the work of two impressive nineteenth-century French historians. A. J. Eagleston made accessible a good deal of this work, including his own researches, but unfortunately his book had to be posthumously published and is therefore rather piecemeal. D. M. Ogier has now published a valuable study of the Reformation in Guernsey. It traces the internal history in depth, stressing the conservatism of the bulk of the population and skilfully elucidating the crucial question of ecclesiastical property, before going on to its main concern, the impact of the Presbyterian discipline on island society. Although Ogier acknowledges the significance of relations between the English crown and various French parties in explaining events, he does little to elucidate these interactions; nor does he display much interest in the personalities involved in his story. This article will attempt to explain both the reluctance of successive English governments to challenge the rights of the bishop of Coutances, and the apparent inability of the Elizabethan government to prevent French Protestant refugees moulding the island churches in their own image. It will also look at some of the leading figures involved, most notably one John Aster, dean of Guernsey, a prime mover in the events of the 1560s, whose career in military administration before his ordination at the age of fifty has not been noticed; and more generally it will emphasise the link between militant Protestantism and the worlds of diplomacy and espionage.