Birth, anniversary, court battle ... 
and Queen’s remarkable milestone

The arrival of a brother or sister for Prince George will be a highlight of 2015 for the Royal Family
The arrival of a brother or sister for Prince George will be a highlight of 2015 for the Royal Family

For the Royal Family, 2015 means a new addition to the Cambridge household and a major milestone for the Queen.

Baby fever will begin again as the Duke and Duchess of Cambridge prepare for the birth of Prince George’s sibling in April, in the run-up to May’s general election.

Other significant royal events include William’s high-profile trip to China, while the Queen is set to become Britain’s longest-serving monarch in September.

• The royal baby

Although the new royal baby is not expected to ever wear the crown, the arrival of the Prince or Princess is still likely to be a major event as royal watchers await news of the new arrival.

The baby – fourth in line to the throne and the Queen’s fifth great-grandchild – could arrive on William and Kate’s fourth wedding anniversary on April 29 or the 89th birthday of the Queen on April 21. If born late he or she might even arrive on election day – May 7.

There will be other changes for William and Kate as they settle into their newly renovated private residence, Anmer Hall on the Sandringham estate in Norfolk with George, who turns two in July.

William will also begin his post as a pilot for East Anglian Air Ambulance in the spring after completing his intensive training and exams.

• Legal battle over the Prince of Wales’s letters

Judges at the Supreme Court will give their ruling on the dispute over the Prince of Wales’s correspondence with government ministers.

The Attorney General is challenging a decision by the Court of the Appeal that former attorney general Dominic Grieve unlawfully prevented the public seeing the letters.

The case stems from a nine-year battle by Guardian journalist Rob Evans to see a number of letters between Charles and government ministers between September 2004 and April 2005 in a freedom of information request.

The Prince has faced accusations in the past of ‘’meddling’’ in day-to-day politics and criticism over his ‘’black spider memos’’ – the name given to the hand-written correspondence he pens to government ministers expressing his views.

• Royal tour to China

William will carry out his most sensitive overseas tour when he travels to China.

The trip in February and March, which is being combined with a visit to Japan, will be an attempt to improve diplomatic relations with the country.

Just days after William’s visit was announced, a row between London and Beijing over China’s refusal to allow British MPs to visit Hong Kong escalated, with Downing Street describing the decision as “mistaken” and “counter-productive”.

Chinese embassy officials told the chairman of the Foreign Affairs Select Committee that a House of Commons delegation would be refused entry to the former British overseas territory for a visit to assess progress towards democracy.

Hong Kong has seen violent clashes on the streets between the police and pro-democracy campaigners.

William is likely to bring up the issue of illegal wildlife trade in the country.

The Duke’s trip will also put a spotlight on his father’s uneasy relationship with China, particularly after Charles described its leaders as ‘’appalling old waxworks’’, and raise questions about why he has yet to make an official visit to the mainland.

• The Queen overtakes Queen Victoria’s record

The Queen is set to become the longest reigning monarch in British history on September 9 2015 when she will pass the record set by her great-great-grandmother, Queen Victoria.

Buckingham Palace has calculated that Victoria reigned for 23,226 days, 16 hours and 23 minutes, taking into account 63 years, 15 leap days, additional months and days and the precise timings of her accession and death.

Queen Elizabeth II will enter the history books when she overtakes Victoria during September 9 2015. This takes into account 63 years plus 16 leap days, additional months and days and the timing of George VI’s death.

It is likely to be business as usual for the monarch when she reaches the landmark date at the age of 89 as she will be at Balmoral where she traditionally spends the month of September.

• Charles and Camilla’s 10th wedding anniversary

On April 9, the Prince of Wales and the Duchess of Cornwall celebrate 10 years of marriage.

A decade on from when Charles wed his former mistress at the Windsor Guildhall in 2005, Camilla’s role within the Royal Family has changed significantly.

She has made appearances at the State Opening of Parliament two years in a row, regally decked out in a white gown, sash and diamond tiara, carried out joint engagements with the Queen and in November hosted a reception on behalf of the monarch for the Commonwealth Essay competition.

•Prince Charles attends Commonwealth conference

The bi-annual Commonwealth Heads of Government Meeting (CHOGM) takes place in Malta in 2015. In 2013, the Queen sent the Prince of Wales to Sri Lanka in her place and missed the summit for the first time since she stayed away from the inaugural one in Singapore in 1971.

It was the first time Charles had been to an overseas CHOGM and was seen as an important event for the heir to the throne.

Although the Queen is head of the Commonwealth, until recently it was thought Charles would not automatically take on the role when he becomes King. A repeat trip to CHOGM for the Prince will cement his position as taking on more of his mother’s duties as she nears her 90th birthday.

• Zara Phillips gears up for the Olympics in 2016

Equestrian eventer Zara will focus on her goal of making the Olympic squad. The equestrian eventer, who won a silver at the London 2012 games, helped Britain secure its place in Rio 2016 with a team silver in the World Equestrian Games in Normandy, France.

Zara, who gave birth to first child Mia in January, will be hoping to make Team GB with challenges such as the 2015 European Championships.

The Queen’s granddaughter has likened motherhood to dealing with horses. “I’ve really enjoyed it. In a funny kind of way it’s like having another type of high-performance horse on your hands,” she told CNN.