Robert Tyrwhitt, the second son of Sir Robert Tyrwhitt, was born in around 1504. He acquired substantial landholdings and was knighted in 1543. Tyrwhitt was on the staff of Queen Catherine Parr and in 1545 became Member of Parliament for Lincolnshire.
Thomas Seymour sought to win the support of Edward VI and gain acceptance as his intimate adviser. He regularly visited Edward's bedchamber. Antonia Fraser has claimed: "He showed no greater greed than the rest of the nobility round him. Seymour's real weakness was his morbid jealously of his elder brother Somerset, whose military victories had first marked him out before his position as Protector raised him up." (1)
When his brother, Edward Seymour, Duke of Somerset, discovered what was happening he "put a special watch on all doors leading into the king's privy chamber in order to prevent Sudeley's clandestine entry". One night Thomas found the door to Edward's bedchamber bolted; enraged, he shot dead the king's barking dog. Somerset was given copies of letters that Sudeley had been passing to Edward. "Somerset found such correspondence intolerable" and ordered his brother's arrest in January, 1549. (2)
Elizabeth's governess, Katherine Ashley, and Sir Thomas Parry, the head of Elizabeth's household, were also arrested and interviewed by Sir Robert Tyrwhitt. They both provided accounts of Thomas Seymour's relationship with Elizabeth. On 22nd January, 1549, Tyrwhitt had a meeting with Elizabeth. He reported to Edward Seymour "all I have gotten yet is by gentle persuasion, whereby I do begin to grow with her in credit... this is a good beginning, I trust more will follow." (3)
On 28th January, Elizabeth wrote a letter to the Lord Protector denying that she was pregnant: "Master Tyrwhit and others have told me that there goeth rumours abroad which be greatly both against my honour and honesty, which, above all other things, I esteem, which be these, that I am in the Tower, and with child by my Lord Admiral (Thomas Seymour). My lord, these are shameful slanders, for the which, besides the great desire I have to see the king's majesty, I shall most heartily desire your lordship that I may show myself there as I am." (4)
The Lord Protector wrote back to her to say that if Elizabeth could identify anyone who uttered such slanders against her, the Council would have them punished. Elizabeth replied that she was unwilling to accuse specific people but suggested a better plan of action: "It might seem good to your lordship, and the rest of the council, to send forth a proclamation into the countries that they refrain their tongues, declaring how the tales be but lies, it should make both the people think that you and the council have great regard that no such rumours should be spread of any of the King's majesty's sisters (as I am, though unworthy) and also that I should think myself to receive such friendship at your hands as you have promised me, although your lordship showed me great already." (5)
Sir Robert Tyrwhitt attempted to discover if Katherine Ashley, Elizabeth and Sir Thomas Parry were involved in what was described a "marriage plot" with Thomas Seymour. However, they all refused to confess and Tyrwhitt reported, "They all sing the same song and so I think they would not do, unless they had set the note before." However, without confessions, Tyrwhitt was forced to release Ashley and Parry but Seymour was charged with 39 articles of treasonable activities, including that he "had attempted and gone about to marry the King's Majesty's sister, the Lady Elizabeth, second inheritor in remainder to the Crown." (6)
Thomas Seymour was examined on 18th and 23rd February but refused to answer unless his accusers stood before him. (7) Seymour demanded an open trial to face his accusers but this was denied. To prevent his brother, Edward Seymour, from showing leniency, the Council gained permission to act without the Lord Protector's authorization. On 20th March, 1549, Seymour was beheaded on Tower Hill. Even on the scaffold, Seymour refused to make the usual confession. Bishop Hugh Latimer commented: "Whether he be saved or no, I leave it to God, but surely he was a wicked man, and the realm is well rid of him." (8)
He was appointed High Sheriff of Cambridgeshire and Huntingdonshire for 1557–58. He had married twice: firstly Bridget, the daughter and heiress of Sir John Wiltshire of Stone Castle, Kent and widow of Sir Richard Wingfield of Kimbolton, Huntingdonshire and Sir Nicholas Harvey of Ickworth, Suffolk and secondly Elizabeth, the daughter of Sir Goddard Oxenbridge of Brede, Sussex.
Robert Tyrwhitt died at Leighton Bromswold on 10th May 1572.
By now, Thomas Seymour's various schemes had been reported to the Privy Council, and the Bristol Mint had been investigated. Sir William Sharington, arrested for embezzling, had informed against Thomas. But it was Thomas himself who made matters worse and, in a sense, brought about his own downfall. On the evening of 16 January, Thomas broke into Hampton Court Palace and tried to seize the King from his bed as he slept. He and a small gang used stolen keys to get as far as the antechamber, and when one of Edward's dogs began to bark, Thomas shot it. The King's guards rushed in and escorted Thomas out as he pled, "I wished to know whether his Majesty was safely guarded."
On the following day, an order was issued for Thomas's arrest. He was dining with the Earl of Dorset when troops came to take him to the Tower of London. Within two days, William Paulet, Lord St John, Sir Anthony Denny and Sir Robert Tyrwhitt had arrived at Hatfield to interview Elizabeth and those in her service: they were suspected of being involved in Thomas's schemes - particularly his plot to marry Elizabeth.
Kat Ashley and Thomas Parry were arrested and taken to London. Sir Robert Tyrwhitt remained at Hatfield to take a statement from Elizabeth, a task he found increasingly onerous. At first Elizabeth "was marvellous abashed and did weep very tenderly a long time" when she heard that Parry and Kat Ashley had been arrested. Elizabeth acknowledged she had written to Thomas Seymour regarding the help he was to give her in getting Durham Place back. She also recalled that Kat had written to him to warn him against visiting `for fear of suspicion', and that she had been angry with her Governess for being so presumptious.