Celebrity baby names: Charlton
The 40-year-old singer tweeted the name, along with a video of his wife wheeling him out of the hospital holding his son in his arms, saying: 'Charlton Valentine Williams has left the building...and Daddy is doing just fine. RW x'
Robbie and Ayda are also parents to daughter Theodora 'Teddy' Rose.
Charlton is an English surname meaning 'settlement of free man', but has become more popular as a first name in recent years.