2015 saw the Queen make history as she became Britain's longest reigning monarch.
It was also a royal baby year when the Duke and Duchess of Cambridge's daughter Princess Charlotte was born in the run-up to the general election.
There were major lifestyle changes for both William and brother Prince Harry as the Duke began a new job as a helicopter pilot for an air ambulance service and Harry said goodbye to army life, leaving the forces after 10 years.
Meanwhile the Prince of Wales and the Duchess of Cornwall celebrated their 10th wedding anniversary, marking a decade of Camilla as an HRH.
The start of 2015 was, however, a difficult time for the royals when the Duke of York faced allegations in the US in January that he had sex with an under-age teenager.
He spoke out publicly at the World Economic Forum in Davos to ''reiterate and reaffirm'' Buckingham Palace statements dismissing the accusations made in US court documents.
The claims were later removed from civil court records following a federal judge's ruling. Andrew went on to play a prominent role this year in key national events such as representing the Queen at the service of remembrance at the Cenotaph in London to mark the 70th anniversary of VE Day.
In February, William travelled to Japan on an official visit while seven-months'-pregnant Kate stayed at home with Prince George.
Meanwhile it emerged that Harry was to leave the Army - a surprise to many who thought the Prince was focused on a long career in the forces.
William continued his overseas trip, heading to China to pay the highest profile UK royal visit to the country in nearly 30 years.
The Duke promoted "brand Britain", highlighted the illegal wildlife trade and visited the Forbidden City.
The Queen, the Duke of Edinburgh, Charles, Camilla, William and heavily-pregnant Kate gathered for a service at London's St Paul's Cathedral to mark the end of British combat operations in Afghanistan, along with Harry, who served two tours during the conflict.
Kate went on maternity leave at the end of March after a joint engagement with William to the Stephen Lawrence Centre in south London, and the Duke started the training for his new job with East Anglian Air Ambulance.
On April 9, Charles and Camilla celebrated their 10th wedding anniversary. The Duchess - Charles's former mistress - became a HRH and a senior royal on her marriage to the heir to the throne.
The couple spent their special anniversary at their favourite retreat on the Balmoral estate in Scotland where they honeymooned.
Harry embarked on a four-week attachment with the Australian Defence Force, joining in a game of wheelchair Australian Football League with wounded soldiers and going on duty to meet locals of the Wuggubun community in the Kununurra region of western Australia.
Later the same month, he travelled to Turkey to join his father Charles and more than 10,000 people at a dawn service to commemorate the 100th anniversary of the start of the doomed Gallipoli Campaign - one of the worst battles of the First World War.
William and Kate's second child was due mid to late April, but Princess Charlotte Elizabeth Diana of Cambridge did not put in an appearance until May 2 as the nation edged closer to election polling day.
She slept soundly in the Duchess's arms as she made her debut outside the Lindo Wing dressed in a cream knitted bonnet.
Grandfather Charles was delighted at the arrival of his long-hoped for granddaughter, but Harry missed meeting his newborn niece as he was in Australia, followed by an official royal tour of New Zealand.
The same month, the Guardian's 10-year legal battle to view secret letters heir to the throne Charles had written to government departments finally came to fruition.
They showed the Prince had tackled then prime minister Tony Blair over the lack of resources for the armed forces fighting in Iraq and lobbied ministers over badgers and TB, herbal medicine and illegal fishing of the Patagonian toothfish.
Harry left the Army and spent the next three months carrying out voluntary work with conservation experts in Namibia, South Africa, Tanzania and Botswana, joining a team of rangers to prevent poaching of elephants and rhinos.
William, meanwhile, ended his six weeks of unpaid leave following the birth of baby Charlotte and went back to work to continue his helicopter pilot training.
Prince George made his debut at the Trooping the Colour parade, appearing on the Buckingham Palace balcony for the first time. Kate was also there seen for the first time at her first official engagement since she gave birth. The Cambridges released family snapshots taken by the Duchess of George tenderly holding Charlotte.
The national service marking the 10th anniversary of the July 7 terror attacks was attended by the Duke of York, while William joined relatives of victims and survivors at the memorial to the dead in Hyde Park.
George turned two on July 22 but it was Charlotte's christening that was the key royal event of the month.
The Princess was baptised at the Church of St Mary Magdalene at Sandringham, Norfolk, in front of close family and her godparents. The nine week old was wheeled to church by her mother in a vintage Millson pram the Queen once used for Prince Andrew and Prince Edward.
George walked from nearby Sandringham House holding William's hand. It was the public's first glimpse of the family of four together.
William and Kate chose one of Diana, Princess of Wales's nieces, a Middleton cousin of Kate's and three close friends as Charlotte's godparents.
The Duke also began his new role as an East Anglian Air Ambulance helicopter pilot and was pictured on his first day in the job, admitting he was nervous.
The Queen and the Duke of Edinburgh broke away from their annual summer holiday to mark the 70th anniversary of VJ Day, joining veterans and former prisoners of war at a service at St Martin-in-the-Fields church in London.
Kensington Palace accused paparazzi photographers of harassing George and Charlotte, saying they were going to ''extreme lengths'' to get pictures including hiding in cars and staking out a children's play area.
On September 9, the Queen passed the record of 23,226 days, 16 hours and 23 minutes on the throne set by her great-great-grandmother Queen Victoria and became the nation's longest reigning monarch.
She was matter of fact about the achievement. Thanking the nation for their messages as she opened the Borders Railway in Tweedbank on the landmark day, she admitted that the milestone was ''not one to which I have ever aspired''.
She added: ''Inevitably a long life can pass by many milestones. My own is no exception."
William and Kate attended their first ever state banquet at Buckingham Palace, joining the Queen to honour Chinese president Xi Jinping. The Duchess, in a glittering red gown, wore the Lotus Flower tiara which used to belong to the Queen Mother.
The Duke, Duchess and Harry had a night out at the premiere for the new Bond film Spectre with the brothers in tuxedos and Kate in a daring ice blue Jenny Packham gown with a sheer back.
At the end of the month, Harry headed to the US and described the profound effect fighting in Afghanistan had on his life as he and first lady Michelle Obama met injured US military veterans undergoing rehab.
Labour leader and lifelong republican Jeremy Corbyn was sworn in as a member of the Privy Council. It was reported that he did not kneel in front of the Queen, but that he did kiss the monarch's hand.
Harry attended the Royal Variety Performance for the first time and became the butt of host Jack Whitehall's jokes.
The royals also jetted off to far flung places with Charles and Camilla touring New Zealand and Australia during a 12-day trip. They donned cloaks made of kiwi feathers - known as korowai - during a visit to the royal riverside residence of Maori leader Kiingi Tuheitia.
The Prince also met Australia's republican PM Malcolm Turnbull who declared that Charles would be King of Australia - unless there was a constitutional change. Charles also had a birthday barbecue in Perth on the day he turned 67.
Despite cutting back on long haul trips in recent years, the Queen and Philip travelled to Malta - for the Commonwealth Heads of Government Meeting in Valletta - where they were joined by Charles and Camilla.
Harry travelled to Lesotho to open his new children's centre for his charity Sentebale and to South Africa to see one of the country's most dangerous townships to learn about projects using football to educate youngsters against HIV.
Kate and William stayed closer to home - but went abseiling at the Towers Residential Outdoor Education Centre in North Wales. They released new family snapshots of six month old Charlotte at home at Anmer Hall.
Charles opened the COP21 climate talks in Paris in the wake of the terror attacks on the French capital, describing climate change as the greatest threat facing humanity.
Harry continued his stay in South Africa and released moving images taken during his three months in Africa over the summer when he worked on the front line in the fight against poaching. He was pictured lying on the stomach of a sedated elephant which was about to be freed.
Back in the UK he visited the London HIV hospital, Mildmay, where his mother Diana, Princess of Wales helped to break down the stigma surrounding the illness by kissing an Aids patient there.
At the Queen's annual diplomatic reception, Kate stepped out in one of Diana's favourite tiaras for the first time - the diamond and pearl Cambridge lover's knot tiara.
Charles's dealing with government hit the headlines once again when it was found he has been routinely receiving copies of confidential Cabinet papers in an arrangement dating back more than 20 years. Campaign group Republic uncovered the revelation after a lengthy freedom of information battle.