Thomas Bellingham, the Preston diarist, was born about 1646 and had one sister Anne who married Robert Bickerton. Thomas married Abigail, daughter of William Handcock, in 1671, by whom he had three daughters, Jane, Abigail and Anne, and a son, Henry. At the Battle of the Boyne he was William III’s aide-de-camp, and it is possible it is then that he was made colonel, a title that he bore at the time of his portrait shown above. He died in 1721 aged 75.
Bellingham was descended from the Bellinghams of Bellingham, near Hexham, where they were lords of the manor up until the early 14th century when they moved to Burneside, near Kendal. One branch of the family acquired the Levens Hall estate, held by them until its sale by Alan Bellingham at the end of the 17th century. A younger son of the family, Robert Bellingham, who was admitted into the Middle Temple in 1595, was the grandfather of Thomas Bellingham. Robert moved to Ireland where he practised as a lawyer, holding various offices including High Sheriff of County Longford. He was buried at Kendal in 1639.
His son Henry, Thomas Bellingham’s father, was a goldsmith in Dublin who acquired the Gernonstown estate, near Dundalk, around 1660, about the same time at which he was appointed High Sherrif of County Kildare. The estate, extending to some 1744 acres, appears to have been a reward for his support for the Cromwellian campaigns in Ireland in which he may have served as an officer. At the Restoration Henry appears to have managed to accommodate comfortably to the new regime, representing County Louth in the Irish Parliament in 1661.
The estate was renamed Castlebellingham while in the possession of his son, Thomas, who rebuilt Castle Bellingham between 1690 and 1700 after the original building had been destroyed by King James’s troops. It was said to have resembled a Dutch chateau with grounds laid out in Dutch style, but has since been remodelled.
The above short biography is based on the introductions to the two transcripts of Thomas’s diary.
The prime interest in Bellingham for the local history of Preston attaches to his diary and his stay in the town. The diary opens at the beginning of August 1668 and ends abruptly on 12 September 1690. The date of his arrival in Preston is not known but he was in town from at least the 10 November 1687 to judge from entries in Lawrence Rawstorne’s diary. 
What is not clear is what he was doing in Preston. Bellingham is referred to by Rawstorne as ‘Captain’, but nowhere is it specified whether this was a regular army or a militia commission. If he had been a militia officer in Ireland, which would have been understandable given his Gernonstown estate, then he could have been a victim of the Tyrconnel purging of Protestants from the militia to make way for Catholics. As the Protestant occupier of an estate which came to his family as a reward for services to Cromwell and which had been previously occupied by Irish Catholics, he would have been a natural target for the attacks from the native Irish that Tyrconnel incited. In the face of such hostility he might have deemed it expedient to join the many Protestants seeking sanctuary in England. This was clearly the case with his brother-in-law Richard Rochfort and possibly with his sister, Anne Bickerton. Rochfort left Ireland in 1688, being among the Protestants attainted by James II’s Irish parliament of 1689, and had his Westmeath estate sequestered.
Given that he had relatives in Preston, it would be perfectly understandable if Bellingham decided to settle in the town for an extended stay. In fact, it could have been family business that brought him to Lancashire at this time: the affairs of his cousin Alan Bellingham at Levens Hall were threatening the ruin of the estate and Thomas made an eight-day visit to Levens in early August 1688 accompanied by a brother-in-law of Alan Bellingham, as detailed in his diary (which does not specify the reason for the visit).
He was back in Ireland after the Revolution, repairing his ravaged estate and resuming his involvement in Irish affairs, representing Louth in the Irish House of Commons from 1692 until 1713. 
There is no record of his ever returning to Preston after the time of his diary. However, he maintained a correspondence with his relatives in the town, including letters to Alexander Johnson, the husband of his cousin Mary Bellingham, one of which, dated 27 February 1704, gives an indication of Bellingham’s political influence. In it he describes how he had interceded on Johnson’s behalf with the Duke of Ormond,
… who, upon my first mentioning of you to be a relation of Mr Keightley’s, and your Lady a relation of mine, he readily promised to use his interest with the Queen, that you should be made high Sherriffe of Yorkshire for the ensuing year, and commanded me to leave a memorandum of it with Mr Secretary Southwell.
More prosaically, he adds a postscript, ‘I could wish you could send me a good clean dayry mayd, for I want one very much, and I would give any reasonable wages.’ 
 Thomas Bellingham and Anthony Hewitson, Diary of Thomas Bellingham, an Officer under William III (Preston: Toulmin & Sons, 1908), http://archive.org/details/diaryofthomasbel00belluoft; Joseph T. Dolan, ‘Colonel Thomas Bellingham’s Diary’, Journal of the County Louth Archaeological Society 1, no. 2 (1905): 45–60.
 Richard D. Harrison, ‘The Rawstorne Diary, 1687-89’ (typescript, nd), 49, Search Room, Lancashire Archives.
 Major-General Stubbs, ‘County Louth Representatives in the Irish Parliament, 1613-1758’, Journal of the County Louth Archaeological Society 4, no. 4 (1919): 311–17, doi:10.2307/27729225.
 Bellingham and Hewitson, Diary of Thomas Bellingham, an Officer under William III, xiv.