Klay, it’s a weird name isn’t it? It’s not so weird when you consider the parents football Wayne Rooney and his wife Coleen, and celebrities never give their kids normal names.

Klay Anthony Rooney's birth at 02:11 BST was announced by his mother on her Twitter feed. She wrote that he weighed 7lb 11.5oz (3.5kg) and "we're all so happy and doing well". Pamela Satran, who has written numerous books on baby names and runs the site nameberry.com, reckons she knows what’s behind the name. "I think 'tradition' is too grand a term for it," she says, talking about the tendency of celebs to name their kids with the same first letter. "It's a practice that started in the US, at least, in the 1950s when people moved away from being very tradition-bound – with family, religious or cultural names – and started picking names they liked. So that left a lot of room to make up their own, much sillier traditions. One thing people did, just like dressing their children the same, was give them matching names. We certainly love it over here [in the US]."

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Klay is the younger brother to the Rooneys' first son, Kai, three, who was born in November 2009. His dad’s future at Manchester United, the club that just lost 26-year-strong manager Alex Ferguson, is in doubt. The England striker is reportedly unhappy with things at United, and wants a move, but nothing has been confirmed.