A Royal Baby Boy Has Arrived As the whole world knows it's a boy who will some day are king of england. Behind this door, a new family is about to spend their first night together. As we said, two years, three months ago the world cheered the newlyweds on the balcony and her royal highness and her child are doing well. Prince william sent word, quote, we could not be happier. We know it is a curious thing in 2013 to be spectators of the fairytale of a royal family. Tonight the fairytale is familiar to everyone, everywhere and amy robach brings us the news from london. Reporter: There are hundreds of people lining the street, some of them planning to camp out overnight to get that first glimpse of the new royal family hopefully right here on the steps of saint mary's hospital. Kate and william slipped past the anxious photographs kamd outside for more than three weeks. The heir to the british thrown was born. His royal highness, prince of cambridge. Bucking tradition, the royal couple released the announcement of their baby boy via e-mail and then to the pomp and circumstance, the announcement was delivered to buckingham palace. Posted at the gates with the news that mother and baby would doing well, the same easel that brought news of william's birth, the last time a royal heir has been so eagerly awaited. Prince charles uncharacteristically beaming on an official visit to yorkshire today. He was greeted by well wishers but was in the dark with little information he could share about the exciting news. Thank you for the kind wishes. Slowly approaching grandfatherhood. Reporter: Following tractor-trai the arrival of his first grandchild he was overjoyed. Uncle harry waited for the news at his air force base. This moment long awaited since the fairytale wedding two years ago. The new family will live in kensington palace with a specially designed nursery and garden, the palace apartment still under renovation. This royal heir will have a modern upbringing, kate's parents, commoners, are also expected to play an important role. Tonight william and kate are spending their first night with their new son in the hospital together. Tonight a new waiting game begins. Of course people wondering what the duke and duchess will name their new heir and when will we find out? It could take a month like prince charles, a week like william or just 24 hours like harry, diane? Thanks so much amy and we go