To make matters worse it was soon bruited about that the Jesuits， whose very name was sufficient to instil terror， were preparing for an invasion of England. The invading force it was true was small， but it was select. Persons and Campion，[31] both Oxford men， who having gone into exile joined themselves to the Society of St. Ignatius， were entrusted with the difficult undertaking. The government， warned by its spies of their mission， had the ports watched to capture them on their arrival， but the two priests contrived to elude the vigilance of their enemies， and succeeded in arriving safely in London (1580). The news of their arrival could not be kept a secret， and hence they determined to leave London. Before they separated for the different fields they had selected， to prevent future misrepresentation of their aims， Campion wrote an open letter addressed to the lords of the privy council in defence of his views， which letter having been published was known as "Campion's challenge." Persons went through the country from Northampton to Gloucester， while Campion preached from Oxford to Northampton. They took pains to set up a small printing press， which was removed from place to place， and from which was issued sufficient literature to disconcert their opponents. Probably the most remarkable volume published from the Jesuit printing-press was Campion's /Ten Reasons/，[32] addressed particularly to the Oxford students amongst whom it created a great sensation. At last after many hair-breadth escapes Campion was captured at Lyford and committed to the Tower. He had challenged his opponents to meet him in a public disputation， and now that he was in their hands， worn out by his labours and imprisonment， they determined to take up the challenge in the hope that by overthrowing him they might shake the faith of his followers.
But despite his weakness and infirmity they found in him so dangerous and so learned an adversary that the government thought it wiser to bring the controversy to an end， or rather to transfer it to the law courts. Even here the captive Jesuit showed that he was quite able to hold his own with the lawyers. He had been guilty of no treason， he averred； he acknowledged the queen to be his lawful sovereign； but he refused to disown the Bull of Deposition. He was found guilty， condemned to death as a traitor， and was executed with two other priests in December 1581.[33]
During the wild start of alarm and vexation caused by the reports of the rising strength of the recusants， the invasion of seminary priests and of Jesuits， and the help given by Gregory XIII. to the Desmond rebellion， Parliament met (Jan. 1581). An Act was passed immediately making it high treason to possess or to exercise the power of absolving or withdrawing anybody from the established church， and a similar penalty was levelled against those who permitted themselves to be reconciled or withdrawn， together with all aiders or abettors. The punishment decreed for celebrating or assisting at Mass was a fine of 100 marks and one year's imprisonment. Fines of ā20 per lunar month were to be inflicted upon all those who absented themselves from Common Prayer， and if their absence lasted for an entire year the delinquents should be obliged to provide heavy securities for their good behaviour. All schoolmasters or tutors not licensed by the bishop of the diocese were declared liable to a year's imprisonment， and the person who employed them to a fine of not less than ā10 per month. The Act was enforced with merciless severity. Fathers Campion， Sherwin， and Briant were hanged， drawn and quartered at Tyburn (Dec. 1581)；eleven other priests met a similar fate before the end of the following year， and two priests and two school-masters were hanged， drawn and quartered in 1583.[34] The news of the execution of Campion and his fellow labourers created a profound impression on the country.
In reply to the protests that were raised Elizabeth thought at first of issuing an official statement， but in the end the idea was abandoned and Cecil， now Lord Burghley， published anonymously two pamphlets to justify the action of the government. The jails were so filled with popish recusants that in order to escape the expense of supporting them， a plan was formed to convey them to North America， but it could not be executed owing to the opposition of the Spanish Government. The seminary priests did not， however， allow themselves to be drawn away from their work either by the terrors of treason or by the echoes of the wordy war， that was being carried on between Lord Burghley and his friends on one side， and Dr. Allen and his friends on the other. A catechism introduced by them was bought up so rapidly that in a few months it was out of print. A great body of the English noblemen still held the old faith. In the north Catholics were numerous and active， and even in the southern and western counties and in Wales opinion was veering rapidly towards Rome. Had the seminary priests been left free to continue their work， unimpeded by foreign or English political plots on the Continent， it is difficult to say what might have been the result. Unfortunately new plots were hatched under the protection of France or Spain for the release of Mary Queen of Scotland， and for her proclamation as Queen of England. Throckmorton， who had taken the principal part in this affair， was arrested and put to death； the principal conspirators， men like the Earl of Northumberland and the Earl of Arundel were sent to the Tower； the jails were filled with Catholics， and five priests were put to death at Tyburn (1584).[35]
