Tantrums and tiaras
Prince Harry's family on Princess Diana's side have strong links with Ireland, and his ancestors, the Roches, owned the Trabolgan estate in East Cork.
Harry is not the first in that line of the family to marry an American - and the omens from past history are not positive.
Diana's great grandfather James Boothby Burke Roche (below) was a gambler and spendthrift who married a wealthy American woman, Frances 'Fannie' Work, daughter of a rich banker.
The couple lived on her wealth and, Roche used her money to fund his gambling.
He sent her over to the US to seek more funds from her father and she travelled with her daughter while he kept the couple's two sons. But by this stage, the rich banker father-in-law had had enough and refused to pay any more for Roche's profligate ways.
The marriage came to an end and this culminated in James abandoning his two toddler sons on the doorstep of his father-in-law's home in New York and making off in a carriage.
He later became an MP for East Kerry.
According to local lore in East Cork, another of Harry's ancestors lost the Trabolgan estate in a bet with a guest on a greyhound race. He thought he had a champion greyhound, but the errant dog spotted a crow and chased the bird rather than the hare, and Roches' family estate was gone forever.
Queen Victoria visited Dublin on a number of occasions. On her last tour of Ireland, known as the "Boer War Tour" of 1900, she was greeted by a crowd of 200,000 in the capital. The public was delighted to have the day off, and trams were "crammed to suffocation" according to reports.
The visit is also remembered for a notorious misprint, possibly deliberate, that appeared in the Dublin Evening Mail. The paper reported: "A large crowd cheered as the royal party pissed over Carlisle Bridge."
As Meghan Markle copes with the troubles in her family, royal watchers point out that there is nothing new about pre-marital disasters. In 1736, Princess Augusta (below) was so horrified at the prospect of being wed to Frederick, Prince of Wales that she vomited over her dress and over Queen Caroline on the way up the aisle.
In 1795, the future George IV was so horrified when he met his fiancée, Caroline of Brunswick that he called for a stiff brandy, and during the wedding ceremony he was worse for wear. Caroline later recorded that he was so intoxicated that he "passed the greatest part of his bridal night under the grate, where he fell, and where I left him".
Meghan Markle's father Tom is said to be of Dutch-Irish extraction.
According to the website Irishcentral.com, her great-great-great-grandmother Mary Smith emigrated to London from Ireland and married a British soldier named Thomas Bird sometime in the mid-1800s. Her Irish family apparently disowned her, and the couple moved to America.
According to somewhat tenuous claims on a Channel 4 documentary this week, Meghan is also related to a Victorian-era murderer suspected of being Jack the Ripper. Markle was reported to be distant relative of Dr H H Holmes, a man dubbed 'America's first serial killer', who some suspect may have carried out the Whitechapel murders on a trip to London.
In 1961 Princess Margaret became the first royal to visit Ireland for more than three decades when she travelled with her new husband, Lord Snowdon, to Birr Castle in Co Offaly. On a later visit there were republican protests and when she visited Abbeyleix House, there was an explosion nearby, caused by the cutting down of an electricity pole.
In October 1979, the princess caused some controversy when she was reported as saying at a dinner in Chicago that "all Irish are pigs".
She insisted that the remark had been misquoted and that she had actually said "all Irish dance jigs".