Elizabeth I
The political "old guard" began to change around the time Coke became a Member of Parliament. The Earl of Leicester died in 1588, followed by Sir Walter Mildmay, the Chancellor of the Exchequer, a year later, and Sir Francis Walsingham a year after that. In 1592 the Lord Chief Justice died and, according to custom the Attorney General, John Popham, succeeded him, with the Solicitor General, Thomas Egerton, succeeding Popham. This created a vacancy among the Law Officers of the Crown, and thanks to the influence of the Cecil family, Coke became Solicitor General on 16 June 1592. This was likely a narrow victory owing to Coke's defence of unpopular clients; he was summoned before Elizabeth I, who berated him until he cried before confirming him as Solicitor General.
Coke held the position only briefly; by the time he returned from a tour of Norfolk to discuss election strategy, he had been confirmed as Speaker of the House of Commons by the Privy Council, having been proposed by Francis Knollys and Thomas Heneage following his return to Parliament as MP for Norfolk. Coke held the positions of Speaker and Solicitor-General at the same time, although he did not take up his post as Speaker until the state opening of Parliament on 19 February 1593 (despite being confirmed on 28 January 1593).
After "disabling" himself in the House of Lords (a ceremony in which the incoming Speaker apologised for his failings) Parliament was suspended until 24 February; Coke returned two days later, having suffered from a stomach problem. The Parliament was intended to be a brief and simple one; with the Black Death resurgent throughout England and the threat of Spain on the horizon, the only matter was to impose certain taxes to fund the Queen's campaign against the Spanish, with no bills to be introduced. The taxes were paramount; subsidies collected in 1589 had been spent, and the war continued.
The idea of a calm, swift Parliament foundered on the rocks of religious conflict. On 27 February James Morice, a Puritan Member of Parliament, proposed two new bills: one against the bishops of the Church of England, and the other against the Court of High Commission. Morice was placed under house arrest, and seven Members of Parliament were later arrested, but the bills remained in Parliament. They were defended by Francis Knollys, one of the few remaining Puritan Members of Parliament, while other Puritans spat and coughed to drown out speeches by opponents.
Coke and Cecil, the government's two strongest defenders in Parliament, made several efforts to put off or end the debate over the bills. Cecil first pointed out that the Queen had forbidden bills on religion; Parliament ignored him, and the bill went ahead. Coke, as Speaker of the House of Commons (whose job was to schedule any bills), conducted a delaying campaign, first suggesting that the bill was too long to be read in the morning and then that it be delegated to a committee; both suggestions were voted down by the Commons. Coke continued talking until the end of the Parliamentary day in a filibuster action, granting a day of delay for the government. Immediately afterwards, Coke was summoned by the Queen, who made it clear that any action on the bills would be considered evidence of disloyalty. The warning was accepted by the Commons, and no more action was taken on the two Puritan bills.
On 10 April 1594, Coke was made Attorney General for England and Wales thanks to his partnership with the Cecil family. Francis Bacon, his rival, was supported by Robert Devereux, who waged a constant war against Robert Cecil for control of the English government. The position of Master of the Rolls had become vacant in April 1593, and Coke was expected to be appointed according to convention; Bacon, therefore, would become Attorney General. Coke reacted by becoming even more dogmatic in his actions on behalf of the Crown, and when Devereux approached the queen on Bacon's behalf, she replied that even Bacon's uncle Lord Burghley considered him the second best candidate, after Coke. The Attorney General was the main prosecutor of the Crown, expected to bring all charges on its behalf and serve as its legal advisor in any situation. Coke was appointed in a time of particular difficulty; besides famine and the conflict with Spain, war had recently broken out in Ireland.
Coke primarily dealt with matters of treason, such as the cases of Sir John Smythe and Edward Squire. He also handled religious incidents such as the disputes between the Jesuits and the Church of England, personally interrogating John Gerard after his capture. As the 1590s continued, the infighting between Cecil and Devereux persisted, with Devereux's raid on Cádiz earning him national fame. In March 1599 Devereux was sent to defeat the growing rebellion in Ireland and was given command of 18,000 men, but by November his army was reduced to 4,000, the rest "frittered away" in exchange for "[conquering] nothing".
On 5 June 1600, he faced a panel of Privy Councillors, judges and members of the nobility at York House, where he was charged with appointing generals without the Queen's permission, ignoring orders and negotiating "very basely" with the leader of the rebel forces. While the members of the nobility wished to be gentle with Devereux, the lawyers and judges felt differently, recommending fines and confinement in the Tower of London. In the end a compromise was reached, with Devereux put under house arrest and dismissed from all his government offices.
Devereux immediately began plotting rebellion. Orders were sent out for "bedding" and "draperies" – codenames for weapons – and rebellious gentlemen gathered at Essex House to hear him talk of Elizabeth's "crooked mind and crooked carcass". In response, Coke and Cecil began a counter-plot. In 1599, Sir John Hayward had written and published The First Part of the Life and Raigne of King Henrie IV, dedicating it to Devereux. Elizabeth, furious, banned the book, suggesting that it was a "seditious prelude" intended to show her as a corrupt and poor monarch. Against the backdrop of Devereux's plot, Coke and Cecil started a new investigation into the book, hoping to prove some involvement of Devereux in the publishing. Coke interviewed Hayward's licensing cleric, Samuel Harsnett, who complained that the dedication had been "foisted" on him by Devereux. In reaction, Coke decided to bring charges of treason against Devereux, saying that he had "plotted and practised with the Pope and king of Spain for the deposing and selling of himself as well as the crown of England ... His permitting underhand that treasonable book of Henry IV to be printed and published; it being plainly deciphered, not only by the matter, and by the epistle itself, for what end and for whose behalf it was made, but also the Earl himself being present so often at the playing thereof, and with great applause giving countenance to it".
The charges were never brought because of an incident that soon transpired. On 8 February 1601 Devereux ordered his followers to meet at Essex House. A day later a group of emissaries led by Thomas Egerton and John Popham were sent to Devereux and immediately taken hostage. After a failed attempt to garner support from the population of London, Devereux found himself surrounded in Essex House; after burning his personal papers, he surrendered. On 19 February he was tried for treason, along with the Earl of Southampton. Coke led the case for the government, and Devereux was found guilty and executed; the Earl of Southampton was reprieved.