The estate of Boyndlie lies about five miles south-west of Fraserburgh in the north-east corner of Aberdeenshire. As the third son of John Forbes, Theodore will have known from boyhood that his future probably did not lie in farming. Some time in the early 19th century, he found himself in the Port of Leith working in a merchant company. Trade with India was brisk and Scottish entrepreneurs had invested so heavily in the tea industry that production outstripped that of China. No doubt through contacts made in Leith, Theodore was promised a position with the East India Company and he boarded a ship bound for the Bombay Presidency. India had been divided into three presidencies or provinces and the others were centred on Calcutta and Madras.

When Theodore arrived in India at the age of 21, he was posted to the port of Surat, about 200 kilometres north of Bombay. His agent was a man known as Aratoon Baldassier and he suggested that Forbes employ a housekeeper. She was Eliza Kewark, an Indian woman probably only two years younger, and his sister-in-law. Her Christian name was almost certainly an anglicised version of Aleeza or Aliza. Not uncommon in the north-west of the subcontinent, it can mean ‘Precious’, or more prosaically, ‘the daughter of Ali’. It may also have been a name popular with the significant Armenian community in India since her father appears in the historical record as Jacob Kevork or Hakob Kevokian. Both versions sound very like typical Armenian names. No record survives of Eliza’s mother, but her sister, the wife of Aratoon Baldassier, had been called Khane, a name with a definite Indian ring to it.

The thriving Armenian enclave in Surat had built a church where they could worship in their version of the Orthodox Christian faith. Researchers believe that Theodore Forbes and Eliza Kewark were married there but that their union may not have been legally recognized by the British authorities. In any event, Theodore wrote in his notebook that his partner was “the very pattern of what a wife ought to be” and in his letters he addressed her affectionately as “My Dear Betsy”.

The Yemeni port of Mocha gave its name to a distinctive flavor of chocolate in Europe perhaps because of its association with the coffee trade. Between the 15th and 17th centuries, there was a busy market in coffee beans at the old port. In the late 18th and early 19th century, the ships of the East India Company anchored in Mocha’s harbor to take on water and supplies and also engage in trade. It was an important staging post and some time after his marriage, Theodore was posted there. He and Eliza found themselves setting up home in Yemen, and in December 1812 they had a daughter, Katharine Scott Forbes. Known as Kitty, she was soon joined by a brother when Alexander was born two years later, in 1814. It seems that the couple’s relationship was stable and settled, a genuine marriage for they went on to have more children. Within a year, Eliza had returned to Surat where she gave birth to another son, Fraser. But, very sadly, the little boy died, aged only six months. At the same time it appears that Theodore had been offered a partnership in Forbes & Co, a busy trading company based in Bombay. The senior partner was a distant relative, Sir Charles Forbes. But attitudes were changing, and after more and more British women and wives came out to settle in India, relationships with native women began to be frowned upon. This shift in social mores persuaded Theodore, or his partners persuaded him, to leave his wife and two children in Surat.

A series of increasingly desperate letters survive. Probably dictated to a scribe (whose English was less than complete) by Eliza, they tell of the agonies of parting as she begged the father of their children to bring his family to Bombay, “I entreat you my dear sir that you may call [us] from hence as soon as possible. Then [I] will be happy and [you will] save my life.” The letters were signed by Eliza in Armenian, and in earlier correspondence, she and Kitty wrote in Hindi. This suggests a mixed Armenian/Indian cultural background. In February, 1818, Eliza wrote again asking for money and added “Kitty and Alexander often ask after their beloved Papa and I let you know they are in good health.” But Theodore was about to let Eliza know that she would never see her children again.

In June 1818, Thomas Fraser, a friend of Theodore, wrote a letter that sounds like part of a longer exchange. He had visited Eliza and the children in Surat and commented, “Kitty retains her good looks but the sooner you give the order about her departure to England, the better as her complexion will soil in this detestable climate”. Perhaps it was darkening too much under the Indian sun, too much for Kitty to be accepted back in Britain without the risk of being tainted as mixed race or ‘of coloured blood’. Theodore decided that his six year-old daughter should be sent back to Boyndlie in Aberdeenshire. Eliza must have been distraught but she insisted that the little girl be accompanied on the long voyage by Fazagool, her faithful servant. She wrote to Theodore, “My good sir, I pray you let me know by your leave I will bring my child to give in your hand by myself and after Kitty is despatched to Europe, then stay in Bombay or Surat.” This passage is from Eliza’s last surviving letter to Theodore – perhaps they were reunited in Bombay. But not for long.

In 1820, Theodore Forbes decided to return to Britain. Having decided to leave Eliza behind, he boarded the SS Blenden Hall but on 24th September, he died and was buried at sea. Perhaps he knew he was mortally ill for he composed a will on board. In it he referred to Eliza as his housekeeper and left her a monthly allowance of only 100 Bombay rupees a month, less than half the amount she had been given before Kitty left for Scotland. To Kitty, described as his ‘reputed natural daughter by Eliza Kewark’, Forbes left 50,000 Bombay rupees. His ‘reputed son’, Alexander, was to have 20,000 rupees, but was commanded to stay in India. But it seems that he did not. There exists a record of a marriage of ‘Alexander Forbes, bachelor, son of Theodore Forbes, merchant in Bombay (deceased) and Eliza Forbes MS Quark (sic) and Elizabeth Cobb in Dundee on 29th June, 1865’. At 51, Alexander was marrying late. Perhaps he had only recently returned from India. He and Elizabeth had two children and probably went to live in Arbroath. If Alexander had spent some time in India before returning to Scotland to be married and begin a family, he may have had knowledge of the family of his aunt and uncle, Aratoon Baldassier and his wife, Khane. If they had had female children, the mtDNA carried by Eliza Kewark may well have lived on in India.

Alexander and Kitty certainly carried the DNA of their mother, and while Eliza’s son could not pass it on, there is no doubt that that shared mtDNA lived on in Katharine Forbes and her descendants.

In the early 19th century and on into the Victorian age, illegitimacy was perhaps less of a stigma in the fermtouns of Scotland than it might have been in the genteel drawing rooms of the cities. Much more of a problem would have been the taint of ‘coloured blood’. But since Katharine’s father had died and her mother remained thousands of miles away in India, it may be that Eliza Kewark’s ethnicity was not an immediate difficulty. Later, she was said to have been an Armenian, perhaps because Kewark or Kevork was recognized as an Armenian surname. Nevertheless, Eliza’s existence was not forgotten or expunged from the family tree. Perhaps that was Katharine’s doing, a stubborn unwillingness to deny her mother, the woman who had born and raised her for at least six years in Surat. It is impossible to do more than guess at what was said and what was not.

In any event, Theodore and Eliza’s daughter, also known as Kitty in Scotland, married James Crombie in Aberdeen. His family became well known for making excellent overcoats. Kitty was 25 years old and very striking looking – looks that were passed down the generations. Her family may have remained pillars of the Scottish middle class had Katharine’s great-granddaughter, Ruth, not married into the aristocracy. Her husband was Maurice Burke Roche, 4th Baron Fermoy, an Irish peer. Ruth became a longstanding member of the household of Queen Elizabeth, the Queen Mother. In 1954 her daughter, Frances, married Edward, Viscount Althorp (later Earl Spencer) and in 1961 gave birth to a daughter, Diana Spencer. A year after her marriage to Prince Charles in 1981, she in turn gave birth to a son, Prince William. In the direct female line, Eliza Kewark’s mitochondrial DNA had been passed down to the heir second in line to the throne of Great Britain and Northern Ireland.

How is it possible to certain of this? Mitochondrial DNA is passed down the motherline to all children. Two living direct descendants of Eliza Kewark have been found and by reading the sequence of their mtDNA, geneticists discovered not only that it matched but that it also belonged to a haplogroup called R30b. Further research confirmed unequivocally that this is Eliza Kewark’s haplogroup. A comparison run through databases of the DNA of more than 65,000 individuals from around the world showed that R30b is very rare and very Indian. Only 14 examples have been reported and 13 of these were Indian, with one in Nepal. To add to this research, it is important to note that the other related branches of R30b, that is R30a and R30, are also entirely South Asian in origin. This confirms beyond doubt that the mtDNA of Eliza Kewark was of Indian heritage.

R30b is rare even in India where only approximately 0.3% of people carry the lineage. And what Eliza passed down to Princess Diana, her other living descendants and to Prince William is even rarer. Within the haplogroup of R30b, an exact match to her sequence has yet to be found outside of her descendants. But Prince William, and Prince Harry, who also carries it, will not be able to pass on their extremely rare Indian mtDNA to their children. They will in turn inherit whatever their mothers’ mtDNA happens to be.

For yet more corroboration, scientists used an independent type of genetic evidence. By reading over 700,000 markers scattered across the genome of Princess Diana’s matrilineal cousins, and comparing findings to a global database of samples, it is possible to estimate the proportions of continental-level ancestry for an individual. For example, someone with a father from Ireland and a mother from Nigeria would be 50% sub-Saharan African and 50% European, or someone with three English grandparents and one from China would be approximately 20% to 30% East Asian. The proportions inherited from ancestors who lived longer ago are lower and also variable. Eliza Kewark’s two descendants are estimated to be about 0.3% and 0.8% South Asian, with three blocks of South Asian DNA in each of their genomes. All of the rest is of European origin.

It is therefore very likely that in addition to his mtDNA, Prince William has not only inherited a small proportion of Indian DNA from Eliza Kewark but that his heirs will also carry it. And in a moving footnote, Princess Diana’s brother, the Earl Spencer, spoke with great feeling at his sister’s funeral of his and his nephew’s blood family. His own daughters are called Eliza and Kitty.