At the age of twelve he appeared at the bar of the House of Commons and pleaded for his father, then in the Tower of London, when his youth, graceful person and well-delivered speech made a great impression. He was admitted to Magdalen College, Oxford, on August 15 1626, where he was a favorite pupil of Peter Heylin, and became M.A. in 1636. He spent the following years in study and in travel, from which he returned, according to George William Frederick Villiers, 4th Earl of Clarendon, the most accomplished person of our nation or perhaps any other nation, and distinguished by a remarkably handsome person.
In 1638 and 1639 were written the Letters between Lord George Digby and Sir Kenelm Digby, Knt. concerning Religion (published in 1651), in which Digby attacked Roman Catholicism. In June 1634 Digby was committed to the Fleet Prison till July for striking Crofts, a gentleman of the court, in Spring Gardens, and possibly his severe treatment and the disfavour shown to his father were the causes of his hostility to the court. He was elected member for Dorsetshire in both the Short and Long parliaments in 1640, and in conjunction with John Pym and John Hampden he took an active part in the opposition to Charles I of England.
On July 15 his speech was burnt by the hangman by the order of the House of Commons. Meanwhile on February 8 he had made an important speech in the Commons advocating the reformation and opposing the abolition of episcopacy. On June 8, during the angry discussion on the army plot, he narrowly escaped assault in the House, and the following day, in order to save him from further attacks, Charles I of England called him up to the Lords in his father's Barony of Digby.
He now became the evil genius of Charles, who had the incredible folly to follow his advice in preference to such men as Edward Hyde, 1st Earl of Clarendon and Lucius Cary, 2nd Viscount Falkland. In November he is recorded as performing singular good service, and doing beyond admiration, in speaking in the Lords against the instruction concerning evil counsellors. He suggested to Charles the impeachment of the five members, and urged upon him the fatal attempt to arrest them on January 4, 1642, but he failed to play his part in the Lords in securing the arrest of Lord Mandeville, to whom on the contrary he declared that the king was very mischievously advised, and according to Edward Hyde, 1st Earl of Clarendon his imprudence was responsible for the betrayal of the kings plan.
Next day he advised the attempt to seize them in the city by force. The same month he was ordered to appear in the Lords to answer a charge of high treason for a supposed armed attempt at Kingston, but fled to the Dutch Republic, wisere he joined Queen consort Henrietta Maria of France, and on February 26 was impeached. Subsequently he visited Charles at York disguised as a Frenchman, but on the return voyage to the Dutch Republic he was captured and taken to Hull, where he for some time escaped detection, and at last he cajoled Sir John Hotham, after discovering himself, into permitting his escape. Later he ventured on a second visit to Hull to persuade Hotham to surrender the place to Charles, but this project failed. He was present at Edgehill, and greatly distinguished himself at Lichfield, where he was wounded while leading the assault. He soon, however, threw down his commission in consequence of a quarrel with Prince Rupert of the Rhine, and returned to the king at Oxford, over whom he obtained more influence as the prospect became more gloomy.
On the 28 September 1643 he was appointed secretary of state and a privy councillor, and on the 31 October high steward of Oxford University. He now supported Henrietta Maria of France's disastrous policy of foreign alliances and help from Ireland, and engaged in a series of imprudent and ill-conducted negotiations which greatly injured the king's affairs, while his fierce disputes with Rupert and his party further embarrassed them. On the 14 October 1645 he was made lieutenant general of the royal forces north of the Trent, with the objct of pushing through to join Montrose, but he was defeated or the 15 October at Sherburn, where his correspondence was captured, disclosing the king's expectations from abroad and from Ireland and his intrigues with the Scots; and after reaching Dumfries, he found his way barred. He escaped on the 24 October to the Isle of Man, thence crossing to Ireland, where he caused Glamorgan to be arrested. Here, on this new stage, he believed he was going to achieve wonders. "Have I not carried my body swimmingly," he wrote to Hyde in irrepressible good spirits, "who being before so irreconcilably hated by the Puritan party, have thus seasonably made myself as odious to the Papists?"
His project now was to bring over Charles, Prince of Wales to head a royalist movement in the island; and having joined Charles at Jersey in April 1646, he intended to entrap him on board, but was dissuaded by Hyde. He then travelled to Paris to gain Henrietta Maria of France's consent to his scheme, but returned to persuade Charles to go to Paris, and accompanied him thither, revisiting Ireland on the 29 June once more, and finally escaping toFrance on the surrender of the island to Parliament. At Paris amongst the royalists he found himself in a nest of enemies eager to pay off old scores. Prince Rupert challenged him, and he fought a duel with Lord Wilmot. He continued his adventures by serving in Louis XIV of France's troops in the war of the Fronde, in which he greatly distinguished himself. He was appointed in 1651 lieutenant-general in the French army, and commander of the forces in Flanders. These new honours, however, were soon lost.
During Jules Cardinal Mazarin's enforced absence from the court Digby aspired to become his successor; and the cardinal, who had from the first penetrated his character and regarded him as a mere adventurer, on his restoration to power sent Digby away on an expedition in Italy; and on his return informed him that he was included in the list of those expelled from France, in accordance with the new treaty with Oliver Cromwell.
In August 1656 he joined Charles II at Bruges, and desirous of avenging himself upon the cardinal offered his services to John of Austria the Younger in the Southern Netherlands, being instrumental in effecting the surrender of the garrison of St. Ghislain to Spain in 1657. On 1 January 1657 he was appointed by Charles II secretary of state, but shortly afterwards, having become a Roman Catholic — probably with the view of adapting himself better to his new Spanish friends — he was compelled to resign office. Charles, however, on account of his "jollity " and Spanish experience took him with him to Spain in 1659, though his presence was especially deprecated by the Spanish; but he succeeded in ingratiating himself, and was welcomed by Philip IV of Spain subsequently at Madrid. By the death of his father Digby had succeeded in January 1659 to the peerage as 2nd Earl of Bristol, and had been made K.G. the same month.
He returned to the Kingdom of England at the English Restoration, when he found himself excluded from office on account of his religion, and relegated to only secondary importance. His desire to make a brilliant figure induced a restless and ambitious activity in parliament. He adopted an attitude of violent hostility to Clarendon. In foreign affairs he inclined strongly to the side of Spain, and opposed the king's marriage with Catherine of Portugal. He persuaded Charles to despatch him to Italy to view the Medici princesses, but the royal marriage and treaty with Portugal were settled in his absence.
In June 1663 he made an attempt to upset Clarendon's management of the House of Commons, but his intrigue was exposed to the parliament by Charles, and Bristol was obliged to attend the House of Lords to exonerate himself, when he confessed that he had "taken the liberty of enlarging," and his comedian-like speech excited general amusement. Exasperated by these failures, in a violent scene with the king early in July, he broke out into fierce and disrespectful reproaches, ending with a threat that unless Charles granted his requests within twenty-four hours "he would do somewhat that should awaken him out of his slumbers, and make him look better to his own business." Accordingly on the 10 July he impeached Clarendon in the Lords of high treason, and on the charge being dismissed renewed his accusation, and was expelled from the court, only avoiding the warrant issued for his apprehension by a concealment of two years.
In January 1664 he caused a new sensation by his appearance at his house at Wimbledon, where he publicly renounced before witnesses his Roman Catholicism, and declared himself a Protestant, his motive being probably to secure immunity from the charge of recusancy preferred against him. When, however, the fall of Clarendon was desired, Bristol was again welcomed at court. He took his seat in the Lords on the 29 July 1667. "The king," wrote Samual Pepys in November, " who not long ago did say of Bristol that he was a man able in three years to get himself a fortune in any kingdom in the world and lose all again in three months, do now hug him and commend his parts everywhere above all the world. He pressed eagerly for Clarendon's committal, and on the refusal of the Lords accused them of mutiny and rebellion, and entered his dissent with "great fury."
In March, 1668 he attended prayers in the Lords. On the 15 March 1673 though still ostensibly a Roman Catholic, he spoke in favour of the Test Act, describing himself as "a Catholic of the church of Rome, not a Catholic of the court of Rome," and asserting the unfitness of Romanists for public office. His adventurous and erratic career closed by death on the 10 March 1677.
Bristol was one of the most striking and conspicuous figures of his time, a man of brilliant abilities, a great orator, one who distinguished himself without effort in any sphere of activity he chose to enter, but whose natural gifts were marred by a restless ambition and instability of character fatal to real greatness.
Clarendon describes him as "the only man I ever knew of such incomparable parts that was none the wiser for any experience or misfortune that befell him," and records his extra-ordinary facility in making friends and making enemies. Horace Walpole characterized him in a series of his smartest antitheses as "a singular person whose life was one contradiction." "He wrote against popery and embraced it; he was a zealous opposer of the court and a sacrifice for it; was conscientiously converted in the midst of his prosecution of Lord Strafford and was most unconscientiously a persecutor of Lord Clarendon. With great parts, he always hurt himself and his friends; with romantic bravery, he was always an unsuccessful commander. He spoke for the Test Act, though a Roman Catholic; and addicted him-self to astrology on the birthday of true philosophy."
Besides his youthful correspondence with Sir Kenelm Digby on the subject of religion, already mentioned, he was the author of an Apology (1643) [Thomason Tracts, E. 34 (32)], justifying his support of the king's cause; of a comedy, Elvira (1667) [Printed in R. Dodsley's Select Collection of Old English Plays (Hazlitt, 1876), vol. xv], and of Worse and Worse, an adaptation from the Spanish, acted but not printed.
Other writings are also ascribed to him, including the authorship with Sir Samuel Tuke of The Adventures of Five Hours (1663). His eloquent and pointed speeches, many of which were printed, are included in the article in the Biog. Brit. and among the Thomason Tracts; see also the general catalogue in the British Museum. The catalogue of his library was published in 1680.
Bristol married Lady Anne Russell, a daughter of Francis Russell, 4th Earl of Bedford and Catherine Brydges. They were parents to four children: