A Puritan from an early age, Vane visited North America (1635) and became in 1636 governor of Massachusetts. In 1637 he returned to England and became an administrator (1639) and a parliamentarian (1640). King Charles I of England knighted him in 1640. He steered a moderate but generally pro-Parliament course through the English Civil War.
In August 1642, at the outbreak of war, he was placed upon the committee of defence. In 1643 he was the leading man among the commissioners sent to treat for a league with the Scots. Vane, who was bitterly opposed to the democracy of the Presbyterian system, was successful in two important points. The aim of the Scots was chiefly the propagation of their discipline in England and Wales, and for this they wanted only a "covenant". The English desired a political "league". Vane succeeded in getting the bond termed the Solemn League and Covenant, and further in substituting the whole expression "according to the word of God and the example of the best Reformed churches" for the latter part alone.
He succeeded to the leadership of his party on Pym's death. He promoted, and became a chief member of, the committee of both kingdoms established in February 1644, and was sent to York in the summer of the year to urge Sir Thomas Fairfax and Manchester to march against Prince Rupert of the Rhine, and secretly to propose the king's deposition. In 1645 he was one of the negotiators of the Treaty of Uxbridge. He was, with Oliver Cromwell, a prime mover in the Self-denying Ordinance and the New Model Army, and his adherence to the army party and to religious tolerance now caused a definite breach with the Scots. Vane had argued for freedom of conscience for all religions, a policy directly opposed to Presbyterianism, and his leadership terminated when the latter party obtained the supremacy in parliament in 1646.
During the subsequent struggle, Vane was one of the six commissioners appointed to treat with the army by the parliament, and endeavoured to effect a compromise, but failed, being distrusted by both the Levellers and the Presbyterians. His views of government may be studied in The People's Case Stated, written shortly before his death. "The power which is directive, and states and ascertains the morality of the rule of obedience, is in the hand of God; but the original, from whence all just power arises, which is magistratical and co-ercitive, is from the will or free gift of the people, who may either keep the power in themselves or give up their subjection and will in the hand of another." King and people were bound by "the fundamental constitution or compact", which if the king violated, the people might return to their original right and freedom.
In spite of these free opinions, Vane still desired the maintenance of the monarchy and the constitution. He voted for a declaration to this effect on 28 April, 1648, and had consistently opposed the various votes of "non-addresses". Several communications had already been fruitlessly attempted with Vane from the king's side, through the agency of Lord Lovelace in January 1644, and through that of John Ashburnham in March 1646. Vane now supported the renewal of negotiations, and was appointed on 1 September 1648 one of the commissioners for the Treaty of Newport. He here showed a desire to come to terms on the foundation of toleration and of a "moderate episcopacy", of which Cromwell greatly disapproved, and opposed the shaking off of the conferences.
Vane absented himself from parliament on the occasion of "Pride's Purge" and remained in retirement until after the king's death (January 30 1649), a measure in which he took no part, though he continued to act as a member of the government. On February 14 1649 he was placed on the council of state, though he refused to take the oath which expressed approbation of the king's execution.
Vane proved an able administrator. He furnished the supplies for Cromwell's expedition to Scotland, and was one of the commissioners sent there subsequently to settle the government and negotiate a union between the two countries. He showed great energy in colonial and foreign affairs, was a leading member of the committee dealing with the latter, and in 1651 went on a secret mission to negotiate with Paul de Gondi, Cardinal de Retz, who was much struck with his ability; while his knowledge of foreign policy, in which he inclined in favour of Holland, earned the praise also of John Milton. To Vane, as chief commissioner of the navy, belongs largely the credit of the victories obtained against Van Tromp.
In domestic politics Vane continued to urge his views of toleration and his opposition to a state church. In January 1650 he brought forward as chairman the report of a committee on the regulation of elections. He wished to reform the franchise on the property basis, to disfranchise some of the existing boroughs, and to give increased representation to the large towns; the sitting members, however, were to retain their seats. In this he was opposed to Cromwell, who desired an entirely new parliament and the supremacy of the army representation. On 20 April 1650 Cromwell forcibly dissolved the Long Parliament while in the act of passing Vane's bill. When Vane protested, "This is not honest; yea, it is against morality and common honesty", Cromwell shouted, "O Sir Henry Vane, Sir Henry Vane; the Lord deliver me from Sir Henry Vane!" (Ludlow, Mem. i. 353). This incident created a permanent breach in their friendship.
In his seclusion at Raby, Vane now wrote the Retired Man's Meditations (1655). In 1656 he proposed in A Healing Question (reprinted in the Somers Tracts, vol. vi. ed. Scott) a new form of government, insisting as before upon a Puritan parliament supreme over the army. The seditious movements of the Anabaptists were also attributed to his influence, and on 29 July, 1656, he was summoned before the council. Refusing to give security not to disturb the public peace, he was sent prisoner to Carisbrooke Castle, and there remained until 31 December 1656. He addressed a letter to Cromwell in which he repudiated the extra-parliamentary authority he had assumed. In the parliament of Richard Cromwell he was elected for Whitchurch, when he urged that the protector's power should be strictly limited, and the negative voice of the new House of Lords disallowed.
Subsequently he allied himself with the officers in setting aside the protectorate and in restoring the Long Parliament, and on Richard Cromwell's abdication he regained his former supremacy in the national counsels. He was a member of the committee of safety and of the council of state appointed in May, was commissioner for the navy and for the appointment of army officers, managed foreign affairs and superintended finance. He adhered to Lambert, remained a member of the government after the latter had turned out the Long Parliament, and endeavoured to maintain it by reconciling the disputing generals and by negotiating with the navy, which first deserted the cause. In consequence, at the restoration of the Long Parliament he was expelled the House and ordered to retire to Raby.
At the Restoration Vane was imprisoned in the Tower of London by the king's order. After several conferences between the houses of parliament, it was agreed that he should be excepted from the indemnity bill, but that a petition should be sent to Charles asking that his life might be spared. The petition was granted. On the meeting, however, of the new parliament of 1661, a vote was passed demanding his trial on the capital charge, and Vane was taken back to the Tower in April 1662 from the Scilly Isles, where he had been imprisoned. On 2 June 1662 he appeared before the king's bench to answer the charge of high treason, when he made a bold and skilful defence, asserting the sovereign power of parliament in justification of his conduct. He was, however, found guilty, and executed on Tower Hill on 14 June 1662.
Vane had married, in 1640, Frances, daughter of Sir Christopher Wray of Barlings, by whom he had a large family of sons and daughters. Of these Christopher, the fifth son, succeeded to his father's estates and was created Baron Barnard by William III.
Vane's great talents as an administrator and statesman have been universally acknowledged. He possessed, says Clarendon, "extraordinary parts, a pleasant wit, a great understanding, a temper not to be moved", and in debate "a quick conception and a very sharp and weighty expression". His patriotism and assiduity in public service, and complete freedom from corruption, were equally admirable and conspicuous.
The religious writings, apart from his constant devotion to toleration and dislike of a state church, are exceedingly obscure both in style and matter, while his enthusiasm and fanaticism in speculative doctrine combine curiously, but not perhaps incongruously, with exceptional sagacity and shrewdness in practical affairs. "He had an unusual aspect," says Clarendon, "which ... made men think there was something in him of the extraordinary; and his whole life made good that imagination."
Besides the works already mentioned and several printed speeches, Vane wrote: