The same practical temper broke out in a more startling innovation. Against dissidents from the legal worship of the Church the Presbyterians were as bitter as Laud himself. But Nonconformity was rising into proportions which made its claim of toleration, of the freedom of religious worship, one of the problems of the time. Its rise had been a sudden one. The sects who rejected in Elizabeth's day the conception of a National Church, and insisted on the right of each congregation to freedom of worship, had all but disappeared at the close of the queen's reign. Some of the dissidents, as in the notable instance of the congregation that produced the Pilgrim Fathers, had found a refuge in Holland; but the bulk had been driven by persecution to a fresh conformity with the Established Church. As soon however as Abbot's primacy promised a milder rule, the Separatist refugees began to venture timidly back again to England. During their exile in Holland the main body had contented themselves with the free developement of their system of independent congregations, each forming in itself a complete Church, and to these the name of Independents attached itself at a later time. A small part however had drifted into a more marked severance in doctrine from the Established Church, especially in their belief of the necessity of adult baptism, a belief from which their obscure congregation at Leyden became known as that of the Baptists. Both of these sects gathered a Church in London in the middle of James's reign, but the persecuting zeal of Laud prevented any spread of their opinions under that of his successor; and it was not till their numbers were suddenly increased by the return of a host of emigrants from New England, with Hugh Peters at their head, on the opening of the Long Parliament, that the Congregational or Independent body began to attract attention. [Sidenote: The Parliament and Uniformity.]