"He was my grandpa: master of the barbecue, legend of banter, and cheeky right ’til the end," said Prince Harry.
British princes William and Harry have paid tribute to the Duke of Edinburgh, the Queen's husband, who died on Friday aged 99.
The brothers, aged 38 and 36, became the latest in the family to honour Prince Philip’s service to the nation.
William, the Duke of Cambridge, who is second in line to the British throne, has pledged "to get on with the job" of serving Queen Elizabeth II.
"My grandfather's century of life was defined by service - to his country and Commonwealth, to his wife and Queen, and to our family," he said in a statement published on Monday on Twitter.
"I feel lucky to have not just had his example to guide me, but his enduring presence well into my own adult life - both through good times and the hardest days.
"I will always be grateful that my wife had so many years to get to know my grandfather and for the kindness he showed her.
"I will never take for granted the special memories my children will always have of their great-grandpa coming to collect them in his carriage and seeing for themselves his infectious sense of adventure as well as his mischievous sense of humour!"
Prince Harry, who currently lives in California, has confirmed he will be returning to the UK on Saturday, April 17 for his grandfather’s funeral.
His office also issued a statement on Monday, in which the Duke of Sussex described Philip as a man who was "authentically himself".
“He will be remembered as the longest-reigning consort to the monarch, a decorated serviceman, a Prince and a Duke,'' Harry said. “But to me, like many of you who have lost a loved one or grandparent over the pain of this past year, he was my grandpa: master of the barbecue, legend of banter, and cheeky right ’til the end.''
Harry signed off his message with the words "Per Mare, Per Terram", meaning "by sea and by land" in Latin: the motto of the Royal Marines, in which he and Philip both served.
Queen's Instagram tribute to Prince Philip
Last Sunday several members of the Royal Family spoke to the media while attending the Royal Chapel of All Saints in Windsor. The Queen’s son Prince Andrew told reporters his passing had left a “huge void” in the monarch’s life.
The royal family also shared a picture of the Queen and Prince Philip on their official Instagram account, which included a touching quote from the Queen herself on her husband of 72 years.
The caption, citing comments made by Her Majesty in 1997, read: “He has, quite simply, been my strength and stay all these years, and I, his whole family, and this and many other a countries, owe him a debt greater than he would ever claim, or we shall ever know.”
The funeral will take place at Windsor Castle on Saturday in a televised ceremony closed to the public.
Prime Minister praises Duke of Edinburgh’s irreverence
Earlier on Monday, Britain's House of Commons was recalled early from its Easter recess and MPs also began offering tributes to Prince Philip.
Speaking in the chamber, Prime Minister Boris Johnson praised the Duke’s “unfailing dedication” to the country, including his service in the Second World War and charity work.
He said it was “fitting” the Duke will be conveyed to his final resting place in a Land Rover he designed himself: “He was, above all, a practical man who could take something very traditional… and find a way, by his own ingenuity, to adapt it for the 20th and the 21st century."
Johnson also made a pointed reference to past off-colour remarks made by the Duke, which had led to some accusing him of racism.
"It is true that he occasionally drove a coach and horses through the finer points of diplomatic protocol,” the Prime Minister said. “He coined a new word, dontopedalogy, for the experience of putting your foot in your mouth.
“He commented adversely on the French concept of breakfast, he told a British student in Papua New Guinea that he was lucky not to be eaten, and the people of the Cayman Islands that they were descended from pirates, and that he would like to go to Russia, except that, as he put it, 'the bastards murdered half my family'.
“The world did not hold it against him. On the contrary, they overwhelmingly understood that he was trying to break the ice, to get things moving, to get people laughing and to forget their nerves."
“He gives us all a model of selflessness and of putting others before ourselves,'' Johnson said. “He made this country a better place.”