Middleton, a commoner who marries Prince William on Friday, is a distant cousin of "The Star-Spangled Banner" author Francis Scott Key, talk-show host Ellen DeGeneres and Colonial Maryland governor Sir Thomas Bladen, the namesake of Bladensburg, according to "The Ancestry of Catherine Middleton."
Released this month by the New England Historic Genealogical Society, the book traces Middleton's roots back hundreds of years, and ties the 29-year-old to a host of historical figures, from George Washington to World War II Gen. George S. Patton.
"We wanted to show how there were some more immediate connections to people with American ancestry and how they might be able to tie in," said Chris Child, a genealogist with the society who helped edit and write the book.
Middleton's American relatives aren't exactly close kin — she and Key are 13th cousins three times removed, and she and Bladen are sixth cousins eight times removed. But they do share some of the same ancestry. Middleton's ancestor Alicia Arnold, who married John Ross and immigrated to Maryland in 1723, was Key's great-grandmother, according to the book. A portrait of Arnold's daughter, Ann Arnold Ross, is on display at the Maryland Historical Society.
While Prince William's lineage can be traced almost exactly for hundreds of years, Middleton's past was murkier, Child said. The book traces one of Middleton's family lines as far back as Sir Thomas Fairfax, who died in 1521.
"That one line was the only one we could trace back that far," Child said. "After a certain point, there are not as many records to trace. Only for families that are in the gentry and nobility can you go that far back."
In 2005, soon after Middleton and Prince William started dating in earnest, genealogist William Addams Reitwiesner, the book's lead author, began researching Middleton's history. To assemble her family tree, he dug through birth, marriage, death and occupation records.
Along the way, he found that Middleton's family is diverse, including butchers, town mayors and ministers. Reitwiesner, who has since passed away, also wrote a book about Princess Diana's genealogy. After Middleton's wedding, the genealogical society is going to send her a copy of the book, Child said.
Middleton is even related to Prince William — they're 14th cousins once removed. Of course, that's nothing compared to Queen Elizabeth and Prince Philip, who are third cousins. Other notable figures in Middleton's family tree: director (and Madonna's ex-husband) Guy Ritchie and writer Upton Sinclair.
It's not uncommon for longtime Marylanders to have roots in English nobility, according to Mark Letzer, the Maryland Historical Society's director of development. In the 1800s, several high-profile English nobles and diplomats married American women. Even Winston Churchill's mother was American, he said.
"We were so English here," he said. "Many [English] families had a second son that would travel to the colonies, or one of their children would travel to the colonies and the family would stay home."
Which means, in theory, that there are everyday Marylanders who share the same blood as the future English princess.
"I guess you can make a case for just about anything," he said.
Royal watching in Maryland
If your invitation to Friday's royal wedding got lost in the mail, fret not — a few area bars and restaurants are throwing wedding-watching parties. Here are two options.
•Slainte may be an Irish pub, but it's rolling out the red carpet for Prince William and Kate Middleton. The festivities begin at 6 a.m., featuring $4 mimosas, $3 Newcastle Brown Ales and a $10 English breakfast. 1700 Thames St. Call 410-563-6600 or go to slaintepub.com.
•At Union Jack's in Columbia, the celebration goes all day, with an English-themed menu including baked beans and bangers and eggs-in-a-basket. And, with more than 25 TVs, the bar has no shortage of wedding coverage. 10400 Little Patuxent Parkway in Columbia. Call 410-740-5225 or go to unionjackscolumbia.com.