The Oath of Engagement, 1649-54
The Oath of Engagement was the declaration of loyalty to the Commonwealth first proposed by Henry Ireton after the execution of King Charles I in 1649. Ireton wanted all members of the Council of State to sign a declaration expressing their approval of the King's trial and execution and of the abolition of the monarchy and House of Lords. When several councillors objected, a compromise was reached whereby they were required to declare loyalty to the republican Commonwealth, but did not have to declare their approval of its past actions.
In October 1649, the Engagement was extended to all Members of Parliament, all clergymen, all members of the armed forces and to all officials in the courts of law, in municipal government and at universities and schools.
Early in 1650, amid alarming rumours of Charles II's alliance with the Scots, Parliament voted to extend the Engagement to all adult males in England. In practice it proved impossible to enforce across the general population, particularly as General Fairfax was among those who objected to it. Many Royalists signed the Engagement with no intention of adhering to it. Its chief opponents were Presbyterian clergymen, who argued that the terms of the Solemn League and Covenant of 1643 precluded their signing the Engagement. Clergymen who might otherwise have lived peaceably organised meetings to debate the legality of the Engagement and denounced the government from their pulpits. In November 1650, Parliament ordered the dismissal of clergymen who refused to take the Engagement.
The Oath of Engagement was finally repealed in January 1654 when Oliver Cromwell became Lord-Protector.
C.H. Firth and R.S. Raitt (eds), Acts and Ordinances of the Interregnum 1911
S.R. Gardiner, History of the Commonwealth and Protectorate vol. i (London 1903)
Blair Worden, The Rump Parliament (Cambridge 1974)