Monaco's Pierre Casiraghi and Beatrice Borromeo have welcomed a baby boy into the world.

 Pierre Casiraghi and Beatrice Borromeo

Pierre Casiraghi and Beatrice Borromeo

The 29-year-old son of Caroline, the Princess of Hanover, and the daughter of Countess Donna Paola Marzotto had their first child together on Tuesday (28.02.17), according to Hello! magazine, with details of the birth yet to be revealed.

It was confirmed back in November that the couple were expecting their first child together.

The 31-year-old beauty was seen at the Copa del Rey Mapfre Sailing Cup awards ceremony sporting a bonny bump.

Their new arrival comes just over a year after the pair held a civil ceremony in July 2015, before jetting off to Italy for a religious wedding on the Borromean Islands in the August.

In March last year, Beatrice opened up about wanting to have a big family, but said she was prioritising securing a stable job first.

She said: "I come from a big family, and I want children of my own. But at the moment I'm thinking about putting my career in a place where it wouldn't get threatened by the presence of children."

Their little bundle of joy is the fourth grandchild for Princess Caroline.

The tot's cousins will be Sacha and India, the son and daughter of Andrea Casiraghi and his wife Tatiana Santo Domingo and Caroline's daughter Charlotte Casiraghi's son Raphaël, whom she shares with ex-boyfriend Gad Elmaleh.