The seeds of discontent at the treatment of Catholics in England, which ultimately led to the failed Gunpowder Plot of 1605, were first sown in the late 1520s during the reign of Henry VIII. Henry had been declared Defender of the Faith by the Pope and had written tracts against Protestantism. However, dissatisfied with the Pope's refusal to grant him a divorce from his first wife Catherine of Aragon, Henry broke away from the See of Rome, extinguished all papal power in England, and executed his investiture as the head of the Church of England. This was followed by the methodical Dissolution of the Monasteries, under the supervision of Thomas Cromwell, which aided the English war chest and was instrumental in eroding the English power of the Catholic Church. Henry's Church of England was initially not Protestant, but remained closer to his traditional belief of Catholicism.

In the turbulent years that followed Henry’s death, England swayed back and forth on a theological pendulum. Henry's successor, his son Edward VI, steered the Anglican Church down the path of Protestantism, whereas his sister "Bloody" Mary I attempted to violently restore England to Catholicism through severe Protestant persecution, until Elizabeth I ascended the throne in 1558, when the tide was again reversed.

Fearful of a now encroaching Catholic Europe, Elizabeth embarked upon a systematic course of repression and persecution of Catholics within her own country, in an attempt to ensure that there was no discontented populace which could assist a foreign invasion, or which could be seen as a beacon if a foreign invasion occurred. When the Spanish Armada was defeated in 1588, Elizabeth had all but extinguished the hopes for an end to persecution of those Catholics in England who saw Spain as their great ally. 

Through her chief ministers, Lord Burghley (William Cecil) and Sir Francis Walsingham, a complex network of government agents and spies was cultivated which only heightened the political tension and succeeded in creating an environment of paranoia and mistrust. It was however moderately successful and resulted in the discovery of plots by Babington, Throckmorton, Somerville, and to some degree, Robert Devereux, Earl of Essex. Elizabeth had her great rival Mary Queen of Scots executed in order to dispel a rallying point for underground Catholic cells and enacted harsh recusancy laws, effectively making Catholics outlaws in their own country. Failure to attend the Protestant Church services had pecuniary retribution, and aiding or abetting Jesuit priests became an act of treason, that was punishable by death.

As Elizabeth's reign closed, the Catholic strongholds in the north of England, who had been instrumental in the Pilgrimage of Grace in 1536/37 and the Norfolk and Northern Uprising of 1569, began sending envoys to both Phillip II of Spain and James VI of Scotland (the son of Mary Queen of Scots). It had become illegal to talk of the succession, yet James was commonly seen as Elizabeth's heir by both Protestants and Catholics, by virtue of closeness of blood to Henry VIII.

James had been seen to curry favour with the English Catholics as well as some of the leading lights of the period, including the Earl of Essex, promising them he would rescind the harsh recusancy laws and allow freedom of worship, so when James eventually succeeded Elizabeth in 1603 as James I, there was initial celebration by the Catholic leaders. James, however, was not to be their saviour. No sooner had the Hampton Court Conference ended, with no compromise being given to either the Puritan faction or the Catholics, than James re-introduced the harsh penalties for recusancy.

With William Burghley and Walsingham now dead, the strong anti-Catholic body within the government was being controlled by Burghley's second son, Robert Cecil, and his cast of henchmen, which included Sir William Waad and Sir John Popham, both of whom played significant parts in the aftermath of the failed Gunpowder Plot.

It was in this theatre of theological persecution that the gunpowder conspirators, disillusioned with James' turn-around, virtually bankrupted through the harsh recusancy laws, and the prospect that this would only get worse, began the engineering of the destruction of James and his Lords. This section looks at some of the key government figures and representatives of the political machinary, and those in high places whose loyalty at times came into question.