Liberal Leader Justin Trudeau announced the arrival of his third child on Friday morning.

Trudeau posted a tweet just after 10 a.m. ET announcing the birth of his son.

Prime Minister Stephen Harper later congratulated Trudeau in a tweet of his own.

As did Opposition NDP leader Thomas Mulcair.

Trudeau has two other children with his wife Sophie Gregoire. His son Xavier James is six and his daughter Ella Grace is five.

It appears Hadrian might be the only little boy with that name. According to Quebec’s online birth registry, no child in the province was named Hadrian between 2007 and 2012. Search results were not available for 2013 and 2014.