During the Jacobite war of 1689-91 James II had no more determined enemies than the Irish presbyterians. But when protestant ascendancy in Ireland was restored under William III, they found that the privileged position of the established church was to remain intact. To English statesmen of the period it seemed that the only essential division of Irish society was that of 'protestant or papist'. But in fact the sub-division of the protestant minority into churchmen and dissenters was in some respects more important. It was a political and social as well as a religious division; and it was one of the forces which stimulated emigration from Ulster to North America during the half century preceding the war of independence.This book is an attempt to explain why this division among protestants persisted in face of a hostile majority of Catholics, and to examine the extent to which the dissenters actually suffered under the penal laws directed against them.