A popular name in Sweden and France (where it is spelt Eugène), Eugen was the favourite at Swedish bookmakers on Tuesday afternoon. It derives from the Greek word eugenes, which means "well born", so it is an apt name for a baby born into a monarchy. The country's most famous Eugen to date is Eugen Napoleon Nicholas, who was Prince of Sweden and Norway in the late 1800s and early 1900s.
More parents picked the name Lucas for their newborn boys in 2014
than any other name, with 860 of the little mites currently crawling around the country. Swedes have a reputation for following trends and conventions, so there is a slim chance that Princess Madeleine and Chris O'Neill could pick this as a safe option. A form of Luke or Lucius, meaning "light-giving" or "illumination", Lucas is also a fitting name for a royal. Although since Sweden is among the most secular nations on the planet, it might not make sense for the modern parents to pick the name of one of the Bible's authors.
Singer William James Adams (will.i.am). Photo: TT
Until 2012, William was the most popular name in Sweden for several years, perhaps made trendy by the marriage of a certain famous British royal or (probably not) former Black Eyed Peas star will.i.am (born William James Adams) enjoying several big solo hits in Scandinavia. The name William has German origins and is said to mean "loyal" or "protector". Perhaps a nod to the Duke of Cambridge might encourage some future playdates with Europe's new royal Princess Charlotte (who is six weeks old as we type this) or maybe even a future Anglo-Nordic wedding. Madeleine and Chris O'Neill are planning to relocate to the UK
later this year, so this possibility is not quite as ludicrous as it might first sound.
The most famous Swedish footballer on the planet
, Zlatan Ibrahimovic, was the inspiration for the most popular potential name picked by readers of Swedish tabloid Aftonbladet on Tuesday. While Swedish historian and author Herman Lindqvist told the newspaper he thought the chance was "very small", arguing that Madeleine's American financier husband had probably never heard of the soccer star ("he probably thinks it's a drink") there are sound public relations reasons why Zlatan could be a good choice for the couple. The star embodies Sweden's open and tolerant approach to immigrants (his parents moved to Sweden from the Balkans), already advertises the nation's best-loved car brand
(Volvo) and with two sons of his own, might even make a good god parent to help his namesake prince improve his skills on the pitch.
5. Gustav or Gustaf
A sketch of Gustav II Adolf. Picture: TT
Sweden's most famous monarchs in history share this name. Under Gustav II Adolf, who ruled between 1611 and 1632, Sweden became a leading military power, and he assumed great political importance by intervening in the Thirty Year's War, one of the longest and most deadly series of battles in European history. More than a century later, Gustav III (ruling between 1771 and 1792) arrived on the scene. He's the Swedish royal known as the Theatre King, because he was a keen patron of the arts, and founded the first opera in Stockholm in 1782, the Swedish Academy and the Royal Academy of Music. Gustaf is also the middle name of the nation's current monarch, King Carl XVI Gustaf
Ask any foreigner to name a famous Swedish name and chances are they'll come up with this one. So Madeleine and Mr O'Neill could do a lot worse than raising a new Björn - if only to make it easier for global journalists to remember. They could even hold the christening party in the new Mamma Mia music venue
being planned by Abba's Björn Ulvaeus. And gifts will be easy, as they could come from former tennis star Björn Borg's extensive clothing collection.
US politician Chuck Hagel at a Nato conference in February 2015. Photo: TT
Chris O'Neill was born in the UK but spent most of his life in the US, where he met his future wife. He has never accepted Swedish citizenship and so might encourage Madeleine to go for a more American name. Chuck is our favourite, allowing the prince to follow in the footsteps of US rock and roll legend Chuck Berry, former US Secretary of State Chuck Hagel, cult action hero Chuck Norris and US pilot Chuck Yeager - the first man to travel faster than the speed of sound. But we'd also love to see a US-inspired prince named Josh, Zac, Brad or Logan.
Chuck Berry wearing a hat similar to those worn by Swedish high school students on graduation day. Photo: TT