In 1555 John Knox returned to Scotland to preach and organize Calvinism. Churches sprang up and many powerful nobles began to listen to him. Brought before an ecclesiastical court (15 May 1556), his prosecution was abandoned, demonstrating the powerful backing he enjoyed. In the latter part of 1557, after Knox had departed for Geneva, these nobles joined together in the Congregation of Jesus Christ, explicitly antagonistic to the Catholic Church. This congregation formed the nucleus of leadership in the wars against the Catholics (1559). But they found it extremely difficult to maintain an army, even with English aid. Their army arrived in Edinburgh 21 October 1559 but soon melted away. The congregation fled 6 November [to Stirling], but in order to maintain support justification for this flight was required.--Description provided by auction house.