At first the fortune of war wavered. Edgehill was a drawn battle (1642), and the campaign of 1643, though it was on the whole favourable to the king, gave no decisive results. Before the year was at an end parliament invited a new Scottish army to intervene in England. As an inducement, the Solemn League and Covenant was signed by all Parliamentarian Englishmen, the terms of which were interpreted by the Scots to bind England to submit to Presbyterianism, though the most important clauses had been purposely left vague, so as to afford a loophole of escape. The battle of Marston Moor, with the defeat of the Royalist forces in the north, was the result. But the battle did not improve the position of the Scots. They had been repulsed, and the victory was justly ascribed to the English contingent. The composition of that contingent was such as to have a special political significance. Its leader was Oliver Cromwell. It was formed by men who were fierce Puritan enthusiasts, and who for the very reason that the intensity of their religion separated them from the mass of their countrymen, had learnt to uphold with all the energy of zeal the doctrine that neither church nor state had a right to interfere with the forms of worship which each congregation might select for itself (see CONGREGATIONALISM and CROMWELL, OLIVER). The principle advocated by the army, and opposed by the Scots and the majority of the House of Commons, was liberty of sectarian association. Some years earlier, under the dominion of Laud, another principle had been proclaimed by Chillingworth and Hales, that of liberty of thought within the unity of the church. Both these movements conduced to the ultimate establishment of toleration, but for the present the Independents were to have their way. The second civil war. Execution of the king. The Presbyterian leaders, Essex and Manchester, were not successful leaders. The army was remodelled after Cromwell's pattern, and the king was finally crushed at Naseby (1645). The next year (1646) he surrendered to the Scots. Then followed two years of fruitless negotiation, in which after the Scots abandoned the king to the English parliament, the army took him out of the hands of the parliament, whilst each in turn tried to find some basis of arrangement on which he might reign without ruling. Such a basis could not be found, and when Charles stirred up a fresh civil war and a Scottish invasion (1648) the leaders of the army vowed that, if victory was theirs, they would bring him to justice. To do this it was necessary to drive out a large number of the members of the House of Commons by what was known as Pride's Purge, and to obtain from the mutilated Commons the dismissal of the House of Lords, and the establishment of a high court of justice, before which the king was brought to trial and sentenced to death. He was beheaded on a scaffold outside the windows of Whitehall (1649).[5] The Commonwealth. Cromwell's protectorate.