He was born in London, the son of Sir William Wentworth, of Wentworth Woodhouse, near Rotherham, a member of an old Yorkshire family, and of Anne, daughter of Sir Robert Atkins of Stowell, Gloucestershire. He was educated at St John's College, Cambridge, became a law student at the Inner Temple in 1607, and in 1611 was knighted and married Margaret, daughter of Francis Clifford, 4th Earl of Cumberland. His relation, another Thomas Wentworth, 1st Earl of Cleveland, fought during the Civil War.
In 1622 Wentworth's wife died, and in February 1625 he married Arabella Holles, daughter of John Holles, 1st Earl of Clare. He represented Pontefract in the parliament of 1624, but appears to have taken no active part. He expressed a wish to avoid foreign complications and "do first the business of the commonwealth."
In the first parliament of Charles I, June 1625, Wentworth again represented Yorkshire, and showed his hostility to the proposed war with Spain by supporting a motion for an adjournment before the house proceeded to business. He opposed the demand for war subsidies made on Buckingham's behalf - after the death of James I, Buckingham had become first minister to Charles - and after that Parliament was dissolved in November, he was made sheriff of Yorkshire, a position which excluded him from the parliament which met of 1626.
In January 1626 Wentworth asked for the presidency of the Council of the North, and was favourably received by Buckingham. But after the dissolution of the parliament, he was dismissed from the justiceship of the peace and the office of custos rotulorum of Yorkshire - which he had held since 1615 - probably because he would not support the court in forcing the country to contribute money without a parliamentary grant. In 1627, he refused to contribute to the forced loan, and was subsequently imprisoned.
In the parliament of 1628, Wentworth joined the popular leaders in resistance to arbitrary taxation and imprisonment, but tried to obtain his goal without offending the Crown. He led the movement for a bill which would have secured the liberties of the subject as completely as the Petition of Right afterwards did, but in a manner less offensive to the King. The proposal failed because of both the uncompromising nature of the parliamentary party and Charles's stubborn refusal to make concessions, and the leadership was snatched from Wentworth's hands by John Eliot and John Coke. Later in the session he quarrelled with Eliot, because he wanted to come to a compromise with the Lords, so as to leave room for the King to act unchecked in special emergencies.
As yet Wentworth was not directly involved in the government of the country. But, and following the assassination of Buckingham, in December, 1628, he became Viscount Wentworth and president of the Council of the North. In the speech delivered at York on taking office, he announced his intention, almost in the words of Francis Bacon, of doing his utmost to bind up the prerogative of the Crown and the liberties of the subject in indistinguishable union. "Whoever," he said, "ravels forth into questions the right of a king and of a people shall never be able to wrap them up again into the comeliness and order he found them." His tactics were the same as those he later practised in Ireland, leading to the accusation that he planned to centralise all power with the executive at the expense of the individual in defiance of constitutional liberties.
The parliamentary session of 1629 ended in a breach between the king and parliament which made the task of a moderator hopeless. Wentworth had to choose between either helping the House of Commons dominate the King or helping the King to dominate the House of Commons. He chose the latter course, throwing himself into the work of repression with characteristic energy and claiming that he was maintaining the old constitution and that his opponents (Parliament) were attempting to alter it. From this time on, he acted as one of two principal members (the other being Archbishop William Laud) in a team of key advisors to the king during an eleven-year period of total monarchical rule without parliament (known both as "the Personal Rule" and the "eleven-year tyranny").
He had to deal with a people who had not arrived at national cohesion, and amongst whom English and Scottish colonists had been introduced (see Plantations of Ireland), some of them, like the early Norman settlers, being Roman Catholics, whilst others preserved their Protestantism. "The lord deputy of Ireland," wrote Sir Thomas Roe to Elizabeth of Bohemia, "doeth great wonders and governs like a king, and hath taught that kingdom to show us an example of envy, by having parliaments and knowing wisely how to use them." Wentworth reformed the administration, getting rid of the inefficient English officials. He manipulated the parliaments to obtain the necessary grants, and secured their cooperation in various useful legislative enactments. He started a new victualling trade with Spain, promoted linen manufacture, and encouraged the development of the resources of the country in many directions.
Customs duties rose from a little over £25,000 in 1633–1634 to £57,000 in 1637–1638. Wentworth raised an army, put an end to piracy, instilled life into the Church and rescued church property. His strong administration reduced the tyranny of the wealthy over the poor. Yet these good measures were all carried out by arbitrary methods which made them unpopular. Their aim was not the prosperity of the Irish but the benefit to the English exchequer, and Strafford suppressed the trade in cloth "lest it should be a means to prejudice that staple commodity of England." Individual cases of unfairness included those of Esmond, Lord Chancellor Loftus and Lord Mountnorris, the last of whom Strafford caused to be sentenced to death in order to obtain the resignation of his office, and then pardoned.
Strafford ignored Charles's promise that no colonists should be forced into Connaught, and in 1635 he raked up an obsolete title—the grant in the 14th century of Connaught to Lionel of Antwerp, whose heir Charles was—and insisted upon the grand juries finding verdicts for the king. One county only, that of Galway, resisted, and the confiscation of Galway was effected by the court of exchequer, while Strafford fined the sheriff £1,000 for summoning such a jury, and cited the jurymen to the castle chamber to answer for their offence. In Ulster the arbitrary confiscation of the property of the city companies aroused dangerous animosity against the government.
Wentworth was unsympathetic towards the Irish as a race. His only thought was to convert them into Englishmen as soon as possible, in their habits, in their laws and in their religion. "I see plainly," he once wrote, "that, so long as this kingdom continues popish, they are not a people for the Crown of England to be confident of." He became even more high-handed.
As yet he had never been consulted on English affairs, and it was only in February 1637 that Charles asked his opinion on a proposed interference in the affairs of the Continent. In reply, he assured Charles that it would be unwise to undertake naval operations until he had secured absolute power at home. He wished that John Hampden and his followers "were well whipped into their right senses." The opinion of the judges had given the King the right to levy ship money, but Wentworth did not consider this enough. When the Scottish Puritans rebelled, he advocated the most decided measures of repression, in February 1639 sending the king £2,000 as his contribution to the expenses of the coming war, at the same time arguing against an invasion of Scotland before the English army was trained, and advising certain concessions in religion.
The Commons, however, insisted on peace with the Scots. Charles, on the advice of—or perhaps by the treachery of—Henry Vane the Elder, returned to his larger demand of twelve subsidies; and on May 9, at the privy council, Strafford, though reluctantly, voted for a dissolution. The same morning the Committee of Eight of the privy council met again. Vane and others were for a mere defence against invasion. Strafford's advice was the contrary. "Go on vigorously or let them alone... go on with a vigorous war as you first designed, loose and absolved from all rules of government, being reduced to extreme necessity, everything is to be done that power might admit... You have an army in Ireland you may employ here to reduce this kingdom...." He tried to force the citizens of London to lend money, and supported a project for debasing the coinage and seizing bullion in the Tower of London, the property of foreign merchants. He also advocated the purchase of a loan from Spain by the offer of a future alliance. Strafford was now appointed to command the English army, and was made a Knight of the Garter, but he fell ill at a crucial moment. In the great council of peers, which assembled on September 24 at York, the struggle was given up, and Charles announced that he had issued writs for another parliament.
By November 1640, there was no other choice but to recall Parliament. The Long Parliament assembled on November 3 1640, and Charles immediately summoned Strafford to London, promising that he "should not suffer in his person, honour or fortune." One of Parliament's first utterances after its eleven-year forced hiatus was to impeach Strafford for "high misdemeanours" regarding his conduct in Ireland. He arrived on November 9 and the next day asked the king to forestall his impeachment by accusing the leaders of the popular party of treasonable communications with the Scots. The plan having been betrayed, John Pym immediately took up the impeachment to the House of Lords. Strafford came in person to confront his accusers, but was ordered to withdraw and taken into custody. On November 25 his preliminary charge was brought up, whereupon he was sent to the Tower, and, on January 31 1641, the accusations in detail were presented. These were that Strafford had tried to subvert the fundamental laws of the kingdom. Much stress was laid on Strafford's reported words: "You have an army in Ireland you may employ here to reduce this kingdom."
By this point, Strafford had become something of a symbol for absolute monarchy, and Parliament felt the need to kill this symbol off. Consequently, the House of Commons produced a bill of attainder which essentially meant that Strafford could be executed regardless of crime, simply because it was the will of Parliament that he should die. On April 13 the Commons passed the bill by a vote of 204 to 59. But the bill could still be blocked in the House of Lords of which Strafford was a member. There was considerable public feeling against Strafford, and the threat of mob violence was sufficient to persuade the Lords to give way. A scheme to win over the leaders of the Parliament, and a scheme to seize the Tower and free Strafford by force, were both considered by the king; and the revelation of the army plot on May 5 caused the Lords to pass the attainder. Nothing now remained but the king's signature.
Strafford had served Charles with what the king felt was a massive degree of loyalty, and Charles had a serious problem with signing Strafford's death warrant as a matter of conscience. However, to refuse the will of the Parliament on this matter could seriously threaten the monarchy, and Charles was keen to stay in power. Charles had, after the passing of the attainder by the Commons, for the second time assured Strafford "upon the word of a king, you shall not suffer in life, honour or fortune." Strafford now wrote releasing the king from his engagements and declaring his willingness to die in order to reconcile Charles to his subjects. "I do most humbly beseech you, for the preventing of such massacres as may happen by your refusal, to pass the bill; by this means to remove... the unfortunate thing forth of the way towards that blessed agreement, which God, I trust, shall for ever establish between you and your subjects." Charles gave his assent on May 10.
Strafford met his fate two days later on Tower Hill, receiving the blessing of Archbishop Laud, who was then also imprisoned in the Tower. He was executed before a crowd of about 200,000 on May 12, 1641. Following news of Strafford's execution, Ireland rose in rebellion in October 1641. This led to more bickering between king and parliament, this time over the raising of an army.
When Charles I was executed eight years later, amongst his last words were that he suggested that God had permitted his execution as punishment for his permitting Strafford's execution.
Strafford had been given the chance to carry out his ideals, and the final failure of his Irish administration, and especially its inability to endure in spite of its undoubted successes, was an object lesson in one-man government for all time. If this was the case in Ireland, where political ideas were still rude and elementary, still less could success be expected from the attempt to introduce the centralization and absolute power of the executive into England, where principles of government had been highly developed both in theory and practice, and a contrary tendency had long been established towards the increase of the rights of the individual and the power of parliament.
In the course of his career he made many enemies. Yet Strafford was capable of inspiring strong friendships in private life. Sir Thomas Roe speaks of him as "Severe abroad and in business, and sweet in private conversation; retired in his friendships but very firm; a terrible judge and a strong enemy." His appearance is described by Sir Philip Warwick: "In his person he was of a tall stature, but stooped much in the neck. His countenance was cloudy whilst he moved or sat thinking, but when he spoke, either seriously or facetiously, he had a lightsome and a very pleasant air; and indeed whatever he then did he performed very gracefully." He himself jested on his own "bent and ill-favoured brow," Lord Exeter replying that had he been "cursed with a meek brow and an arch of white hair upon it, he would never have governed Ireland nor Yorkshire."
In 1662 Parliament reversed the attainder to allow his son William Wentworth to inherit his title.