Denmark's Prince Joachim cried when his wife gave birth Monday. The 39-year-old royal and Princess Marie welcomed a healthy baby boy into the world at 4.57am, after a ten-hour labor at Rigshospitalet in Copenhagen.

The new prince - who is the fifth grandchild of Queen Margrethe - weighed 3kg, and measured 49cm in length.

Joachim held his 33-year-old wife's hand throughout the birth, and admits to shedding a tear as he cut the umbilical cord.

He said: "It was a very moving moment".

The couple - who married in a lavish ceremony in October 2007 - will not announce their son's name until his christening.

The prince said: "As I have said before, it could be anything from Ib to Nebukaneser."

It is Joachim and Marie's first child together. The prince has two other children, Prince Nikolai, nine, and Prince Felix, six, from a previous marriage.

The latest addition to the Danish royal family will be seventh in line to the throne. All public buildings and buses will fly the Danish flag today to celebrate his birth and Kronborg Castle will fire a 21 gun salute at noon.