Gifts given to royals when they were children, including the youngest Prince George, go on display today at Buckingham Palace.
The princes made royal internet history as they appeared for a live question and answer session today.
Hong Kong is acting as the gateway for illegal ivory entering China - where the item is high in demand.
The Royal Family have defended spending a seven-figure sum refurbishing the Duke and Duchess of Cambridge's Kensington Palace apartment.
A royal spokesman said repairs and refurbishments - reported to cost around £4 million, though this figure was not confirmed by the royal household - included "significant amount of internal building" to "return the residence to function as a living space".
William and Kate's Kensington Palace apartment was designed by Sir Christopher Wren and was the home of Princess Margaret and Lord Snowdon. Margaret remained there after their divorce and lived there until her death in 2002.
The living space was last refurbished in 1963.
A royal spokesman said: "This is the Duke and Duchess's one and only official residence. It is here that they plan to stay for many, many years to come."
He said William and Kate "paid privately" for all the internal furnishings, including carpets and curtains.
The cost of renovating the new Kensington Palace home of Duke and Duchess of Cambridge is to reach £4 million pounds, according to reports.
The taxpayer will foot the bill for extensive work on the property, including installing a new roof, overhauling the electrics and carrying out significant plumbing works.
A royal spokesman said repairs and refurbishments - reported to cost in the region of £4 million, though this figure was not confirmed by the royal household - would also see a "significant amount of internal building" to "return the residence to function as a living space".
He said William and Kate "paid privately" for all the internal furnishings, including carpets and curtains. They were also at pains to ensure that the specification is not extravagant.
A ComRes poll has found that Boris Johnson is more popular than the prime minister, while Britons viewed religious freedom as one of the least important "British values".
ComRes interviewed 2,034 British adults online earlier this month.
Politicians in order of popularity:
- London mayor Boris Johnson - 41%
- Prime Minister David Cameron - 28%
- Ukip's Nigel Farage - 26%
- William Hague - 25%
- Labour leader Ed Miliband - 19%
- Theresa May - 16%
- Nick Clegg - 13%
- Michael Gove - 9%
Most important British values:
- Freedom of speech - 48%
- Tolerance - 27%
- A sense of humour - 26%
- Equality - 24%
- Politeness - 22%
- Political freedom - 20%
- Responsibility - 14%
- Religious freedom - 12%
- Aspiration - 3%
British people rate the Duke of Cambridge more highly than his grandmother the Queen, according to ComRes poll.
The 2,000-plus people survey for the Sunday Mirror and Independent on Sunday found that 68% expressed a "favourable" view of the young royal compared with 63% for his grandmother.
But both royals are significantly more popular than the UK's best-known politicians.
The Prince of Wales lagged well behind his mother and son on 43% - but even the heir to the throne enjoyed a better rating than any of the Westminster figures.
The Duke of Cambridge revealed he is a fan of British rockers Coldplay, during a visit to a school in East Yorkshire today.
When William was asked by pupils at Goole High School what music he liked, the Duke was heard to reply: "I really like Coldplay, Linkin Park."
He turned down an offer by pupils who are part of the school's samba band to play one of the drums, telling them: "I used to play the piano, trumpet and drums when I was your age but I couldn't read music.
"There's only so much you can remember from the top of your head."
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Prince William and Prince Harry were back at the polo pitch today, playing a charity match in Coworth Park near Ascot in Berkshire.
The annual charity event in support of charities including the Royal Marsdencancer hospital, HIV fund Sentebale and youth training charity Skillforce.
The Duke of Cambridge has followed in the footsteps of his father, the Prince of Wales, and grandfather, the Duke of Edinburgh, by taking on the role of president of the British Sub-Aqua Club (Bsac).
Speaking exclusively to Scuba magazine he said:
– Prince William
Scuba diving really has opened my eyes not only to many extraordinary sights, but also to the responsibilities that we have as guardians of the underwater world.
I look forward to working with Bsac to encourage even more young people into the sport, for they are the next generation of underwater explorers, pioneers and protectors.
The skills and experiences gained through snorkelling and scuba diving can have a positive and lasting impact on their lives, giving them confidence and building their aspirations.
Bsac chairman Clare Peddie spoke of the Duke of Cambridge appointment saying:
– Bsac chairman Clare Peddie
This is a very proud moment in Bsac's history to welcome the Duke of Cambridge after his father and grandfather before him.
It comes just after Bsac's diamond jubilee and having the Duke at the helm of our organisation as we move into a new era is a huge and special privilege.
It is also a chance for us to say thank you to his father, the Prince of Wales, for the four decades of committed service he has given to Bsac.
Prince George may only be nine months old but his proud father, The Duke of Cambridge, would like to see him in the future experience the "wonders" of snorkelling and scuba diving.
The comments come as Prince William became president of the British Sub-Aqua Club (Bsac) governing body, the third generation of the monarchy to take the helm of president.
In a foreword for the magazine 'Scuba,' the Duke of Cambridge said he hopes his son Prince George will take up scuba diving,
Prince William said: "Just like my grandfather and my father, I am proud to say that I learnt to dive with Bsac, and share your passion for the sport and the underwater world.
"I hope that one day my son, George, will also experience the wonders that snorkelling and scuba diving have to offer."