Katherine, Duchess of Kent, is one of the least known of British royalty.
However, she has been incredibly influential in the history of royalty.
Near the queen, Katherine, Duchess of Kent, converted to Catholicism.
This made history, for she was the first royal to convert since the 1701 Agreement Act.
This act meant that only Protestant Christians could rise to the throne, and any royal who married a Catholic would be disqualified.
Katherine, now 86, is a cousin marrying the queen after marrying her first cousin, Prince Edward, Duke of Kent.
Born in the aristocracy, his father was Sir William Arthington Worsley, 4th Baronet.
She received very little in terms of formal education, having only two qualifications. However, she is a talented musician.
Katherine was proposed by Prince Edward with a sapphire and diamond ring, and they were married in an unusual location, York Minster.
She was wearing a stunning white silk gauze dress by John Cavanagh, who three years later created Princess Alexandra's dress.
The bride wore the tiara Kent Diamond and Pearl Fringe, recently worn by Lady Gabriella Windsor on her wedding day.
The tiara had already been valued at $ 3 million.
Ailsa Russell Gemologist and Appraiser Prestige Pawnbrokers of Channel 4 Posh Pawn said of this piece: “This beautiful set of Russian-inspired tiara gold and silver diamonds originally belonged to Princess Marina of Kent, present before her wedding to the Duke of Kent in 1934.
“Welcoming the Greek and Dutch princess in the country given her by the city of London. It was worn by Princess Alexandra on her wedding day and became another icon of the Royal Kent family's jewelry collection.
“The magnificent design of the graduated fringe is heavily studded with beautifully sparkling diamonds and uniquely for a fringe tiara, it cannot be used as a necklace either.
“Today the diadem is favored by Princess Michael of Kent and has appeared in official portraits and is often worn on state occasions, especially the princess used it for a ball in Vienna on the wedding night.
"Probably, with over 100 cts of diamonds, a diadem of this provenance and importance would probably reach 1 to 3 million pounds."
Katherine was praised when she returned to her teaching career after the tragedy of the Grenfell fire.
Called Mrs. Kent by her students, she teaches part-time music at an elementary school near where the tragedy occurred.
Katherine's husband, Prince Edward, Duke of Kent, is the 37th in line for the British throne.
The real line of succession – who overcomes who?
The line of succession to the British throne determines the order in which each member of the Royal Family would ascend to the throne.
It is also seen as ranking in importance with the head of the line, the queen, taking the place of ruler.
Older children come before younger children. Traditionally, boys came before girls, but this law was amended on March 26, 2015 before the birth of Prince William's first child.
Incredibly, Catholics are still excluded from the line of succession, as are children born out of wedlock.
Royals, who often follow strict protocol when they appear in public, often come to events in ascending order of importance, with the most important royals coming last.
Prince Charles, 70, is currently second in line to the British throne, followed by Prince William, 37, his eldest son.
Then come the sons of Prince William, George, five, Charlotte, three, and Louis, almost one, and are followed by Prince Harry, 34. Prince Harry is succeeded by his son Archie Harrison, born in May.