The Duke of Sussex was a cuddly child who was fearless and mischievous even at a young age.
The second son of the Prince and Princess of Wales, Prince Henry Charles Albert David was born weighing 6lb 14oz, at 4.20pm on September 15 1984.
Palace officials announced that he was to be known as Harry and his father later declared this was always the case unless he had been “very, very naughty”.
Diana was extremely protective of her youngest child, who was affectionate, cuddly and had a sensitive side.
But Harry was also known for his adventurous approach to life.
The princess is said to have referred to him as “my danger-loving Harry”, and the impish child was dubbed the “happy prince” for his cheery nature.
He was also not averse to pulling faces for the camera.
On his way to the nursery nativity play, where he dressed up as a pixie, four-year-old Harry showed he was a true royal rascal by opening his mouth wide and sticking his tongue out at photographers as he went past in a car.
Fearless on the ski slopes even at the age of six, the prince was sporty in his early years.
He was dubbed “Kamikaze Harry” by his nanny in tribute to his daredevil ways.
He was also something of a prankster.
At the age of eight he locked himself in a toilet on board a train just for fun, ignoring Diana’s pleas as she repeatedly banged on the door.
A lover of practical jokes, he liked whoopee cushions and, as a small boy, a favourite trick was to dismantle his parents’ hi-fi at Highgrove.
He would wait to watch their faces as they switched on the stereo and nothing happened.
One member of the Highgrove staff recalled at the time: “If he is reprimanded by a teacher at school, his usual ploy is to mimic his aggressor behind his back and run off laughing.
“Harry is fearless. He is so laid back that very little seems to worry him.”
His love of all things military started early on.
In 1993, the eight-year-old prince, who would later spend 10 years in the forces, beamed with delight as, dressed up in a miniature combat suit and helmet, he sat in a tank during a visit to the German base of the Light Dragoons with Diana on his first formal public engagement.
Diana’s protection officer, Ken Wharfe, once recalled how the young royal, whom he lent a two-way radio, used to dress up in camouflage gear and ask for missions.
But one day Harry took it upon himself to escape from Kensington Palace to Kensington High Street on his own without telling anyone, before calling in with an “Assignment complete” sign-off.
Mr Wharfe said the youngster’s “feet didn’t touch the ground” as he rushed to find his charge after realising where he was.
Harry was, unlike his older brother Prince William, free from the responsibility of one day having to be king.
But he also suffered with the emotional distress of witnessing the breakdown of his parents’ marriage, and the public fallout that followed.
And then when he was just 12, he faced the sudden, tragic death of his beloved mother in a car crash.
The duke, now married to American former actress Meghan Markle and expecting his first child, admitted in recent years that he came close to a breakdown after spending his teenage years and 20s determined not to think about the princess.
But he has looked back on his early childhood fondly, recalling in an ITV documentary as he leafed through family photos of Diana: “Happy memories, big, smiley faces. She smothered us with love, that’s for sure.”