Royal gun salutes echoed through the Danish capital Saturday to mark the birth of Crown Princess Mary's first child, a healthy baby boy who one day is expected to assume the throne of Europe's oldest reigning monarchy. With Crown Prince Frederik by her side, Australian-born Mary gave birth to the boy at 1:57 a.m. Saturday (2357GMT Friday) at the Copenhagen University Hospital, two weeks before her scheduled due date, the palace said. Both mother and child were doing fine. "It is a tremendous joy," a visibly moved and happy Frederik told reporters Saturday morning at the hospital. "It is impossible to describe that feeling for me and my wife, who is doing fine." The little prince was 51 centimeters (20 inches) and weighed 3.5 kilograms (7.7 pounds), the royal palace said in the statement. Queen Margrethe, Frederik's mother, briefly visited the couple and their child. "It is wonderful," she told Danish TV as she left the hospital, adding she didn't hold her grandchild, but waved to him.