Queen Ella? King Terry? What's in a royal name? What will royal baby's name be? As royal baby's arrival date nears, speculation growing as to what he or she will be called Prince William and Catherine are expected to opt for a traditionally "regal" name Experts say "Diana" may be chosen as a middle name, in tribute to baby's grandmother Bookies' favorites are Alexandra and George -- but you can also place bets on unusual names London (CNN) -- Way back in the mists of time, when schoolkids were expected to learn seemingly endless lists of facts off by heart, they chanted a poem to remember the names of England's kings and queens. "Willie, Willie, Harry, Ste," it began. Harry, Dick, John, Harry three / One, two, three Neds, Richard two / Harrys four, five, six, then who? It then ended with the most recent monarchs: "Edward seven, George and Ted / George the sixth, now Liz instead." Of course, it's not done that way any more, but if it were, which name would make it into the next verse? We know that "Charles" and "William" will follow "Liz," but which name will follow theirs? As the due date for William and Catherine's eagerly-awaited baby nears, speculation is growing as to what they'll call the newest addition to the royal family. Will they pick a name that has already featured in that schoolroom poem? "William and Kate are very much a couple of the 21st century but I think they will stick to traditional names, in keeping with the past," Kate's biographer Claudia Joseph told CNN. Currently sitting at the top of the list for a girl is Alexandra, with bookmakers offering odds of 7/2 or 4/1 in favor of the new baby being named after the wife of King Edward VII, Queen Elizabeth II's grandmother. Read more: What will the royal baby look like? "It is the Queen's middle name, and it is very dignified, very traditional, but the very fact that there has been a surge at the bookies may count against it," said historian and author Kate Williams. Prince William can be quite contrary, and he won't necessarily want to choose a name that has been heavily betted on. Instead, Williams wonders if the royal couple might select something simpler. "We live in an increasingly global world, and both Catherine and Alexandra can be quite hard to pronounce for those who don't speak English as a first language," she said. I suspect they might go for something like Mary, which is easy to say. Whatever the pair pick as the all-important first name, there will be plenty of room to fit in nods to other members of the family too. "Royals have quite a lot of names," said Williams. Charles is actually Charles Philip Arthur George, and the Queen is Elizabeth Alexandra Mary. Her father, Bertie, had five names. Writing for CNN, royal author Andrew Roberts agreed: "Although we can't know what the child's name will be, we can be sure that he or she will have a lot of them: Some heirs to the throne [have] had as many as seven or eight. Should they have a girl, it would be surprising if the name is Elizabeth, after her great-grandmother Queen Elizabeth II ... and Diana, after her paternal grandmother ... both are missing from the list. Read more: Will royal baby be a boy or a girl? Williams says that in the case of a girl, she believes Elizabeth (7/1) is likely to be chosen as a second name, with Diana (7/1) third, and a nod to the Middleton family -- perhaps Caroline (40/1), as a link to Kate's mother, Carole (50/1) -- fourth. But Joseph said that naming the baby in partial tribute to Princess Diana was not guaranteed: "They may feel that it would be a heavy burden on the child." Other "royal" names that might make it onto a princess's birth certificate include Charlotte (second favourite, at 11/2, 5/1 and 6/1 at various British bookmakers), Alice (odds on this are running at anywhere from 10/1 to 16/1) Eleanor (currently at 12/1), or even Matilda, after the 12th century Empress Matilda. William and Kate are very much a couple of the 21st century but I think they will stick to traditional names Claudia Joseph, royal biographer Victoria is third favorite, with odds of between 6/1 and 8/1, though Williams insists William and Kate are unlikely to choose it as a first name. "The idea of her being Queen Victoria II might be seen as a bit presumptuous," she said. Williams said the couple's choice in the event of the arrival of a son was simpler in theory, since there are fewer traditionally "royal" male names to choose from. George is the current frontrunner, with odds of between 7/1 and 10/1. "We're very fond of King Georges in this country," she said. Read more: Royal baby -- heir for a new century? But the peculiar British royal tradition of switching between names may complicate matters. Prince Charles is expected to be known as King George VII when he ascends to the throne; King George VI was actually christened Albert; and his brother, Edward VIII, who became Duke of Windsor after his 1936 abdication, was known as David by family and friends. History has also knocked several male names out of the equation: Edward is unlikely, given that scandalous abdication so he could marry American divorcee Wallis Simpson, and the various King Richards, Charleses and Johns are viewed as cruel, tyrannical or just downright unpopular. "Charles, at 10/1, and John, at 8/1, are very unlikely," Roberts wrote. Charles is already taken as the name of Prince William's father, and John was one of the worst kings in British history. King John was forced to sign the Magna Carta by his nobles in 1215; he was portrayed as the key villain in "Robin Hood." "There's no way they would pick Edward as a first name," insists Williams. And you can't have Henry, after Henry VIII (though of course if Harry came to the throne he would be Henry). My bet is on George Philip William Edward. In recent years, there has been a move away from classic "regal" names by those on lower branches of the royal family tree. Prince Andrew and his now ex-wife Sarah "Fergie" Ferguson plumped for the unusual Beatrice and Eugenie for Prince William's cousins. Princess Anne, William's aunt, has two granddaughters by son Peter and Canadian daughter-in-law Autumn Phillips: Savannah (born in 2010) and Isla (born in 2012). Read more: Who can inherit British throne? But Joseph said William and Kate were unlikely to go for more "trendy" options such as Lily, Ella or Ruby, which are a regular feature in annual lists of the most popular baby names. "Obviously other members of the royal family have broken with tradition but the offspring of William and Kate will be a future monarch," she said. That means, says Williams, "we're not going to see a Chardonnay, or a Plum, or an Apple." Nevertheless, British betting shops are more than happy to take your money if you fancy a flutter on a more modern or quirky moniker. BetVictor is offering odds of 20/1 on the couple picking Alberta -- though whether that is in recognition of their hugely successful Canadian tour, or as a feminine version of King George VI's birth name is unclear. According to the bookies, at least, we might one day be chanting "Long Live Queen Esme" (200/1) or celebrating the jubilee of King Ryan (200/1). And if you think the future monarch might name a king-in-waiting after the King, you can always give it a shot: Ladbrokes are offering odds of 500/1 in favor of Elvis. Read more: Royal baby, meet the family! Check out all of CNN's coverage of the royal baby here.