In 1487, during the plot for raising Lambert Simnel to the throne, the citizens, while the insurrection in that impostor's favour was almost universal, maintained a firm and unshaken loyalty to Henry VII. The Earl of Kildare, then lord-deputy, haying proclaimed Sim-nel king in Dublin, sent to the mayor of Waterford, commanding him to receive the pretender and assist him with all his forces; to which, with the advice of the council, he wrote in return, by a messenger of his own, that the citizens of Waterford regarded all the supporters of Simnel as rebels. On the receipt of this answer, the earl ordered the messenger to be hanged. He then sent his herald to command the mayor and citizens to acknowledge and proclaim the new king, on pain of being hanged at their doors; they received this message in the boat, without allowing the herald to land, and sent back word that they hoped to save the false king and his adherents the trouble of coming so far for such a purpose, by meeting him on the road. Preparations for battle were accordingly made, in which the Butlers and other septs then in the city, and men from several other towns, joined the mayor and citi-zens; but the departure of Simnel for England sus-pended further proceedings: he, however, assembled a parliament previously to his embarkation, in which he declared the franchises and the possessions of the city forfeited. Henry VII., to acknowledge the steady loyalty of the citizens, wrote a letter of thanks to them immediately after the battle of Stoke, and empowered them to seize the persons and appropriate the goods of as many of the insurgents as they could secure. Sir Richard Edgecombe, who, after these disturbances, was sent with a considerable force to receive new oaths of allegiance from the leading men in Ireland, arrived in this city from Kinsale, in June, 1488, and was honourably entertained by the mayor and citizens, to whom he promised so to represent matters to the king that, in the event of the Earl of Kildare being again raised to authority, they should be secured from his resentment, by an exemption from his jurisdiction. In a parliament held in 1492, the citizens, who it was stated "had by false surmises been attainted, by authority of parlia-ment, in the time of Gerald, Earl of Kildare, lord-deputy," were formally restored to the enjoyment of their grants, authorities, and privileges.
In the year 1497, they again testified their fidelity by communicating to the king intelligence of the arrival of Perkin Warbeck, at Cork, on a second expedition against Ireland; and by formally assuring him of their loyalty and affection. On this occasion, 'among other honours conferred upon the city, 'was the motto, Urbs inta eta manet Waterford. Perkin, being joined by the Earl of Desmond and his numerous followers, imme-diately marched with an army of 0400 men to attack Waterford, which they assailed on the west; the siege lasted eleven days, during which time the citizens were victorious in several skirmishes. Eleven of the enemy's ships arrived at Passage during the siege, and two of them landed men at Lombard's weir; 'but the troops were quickly overpowered by the citizens, who killed many of them, and carried several into the city as prisoners and beheaded them in the market-place: one of the vessels was sunk in the river by the cannon on Reginald's Tower, and the whole of the crew perished. At length, on the 3rd of August, the enemy, before daybreak, raised the siege, and retired with great loss towards Ballycashin; Perkin embarked at Passage for England, but was pursued by the citizens with four of their ships to Cork, thence to Kinsale, and lastly to Cornwall. In acknowledgment of these distinguished services, the citizens received two letters from the king, in the first of which, previously to Perkin's apprehen-sion, he offers them the sum of 1000 marks to secure his person.