A wide range of commemorative coins are being struck - from the rare kilo coin to the £5 silver which will be more readily available.
The two arrived late after their helicopter was forced to make an emergency landing minutes after taking off from central London.
Tributes have been paid to Princess Lilian, both in Scandinavia and in Swansea where she was born, after her death at the age of 97.
The Prince of Wales and the Duchess of Cornwall survived an emergency helicopter landing last year, it has emerged.
Four other passengers were travelling on the Sikorsky S-76C helicopter on May 23 last year when the aircraft got into trouble, a report by the Air Accidents Investigation Branch (AAIB) said.
The heir to the throne and his wife were on their way to an engagement at the Hay-on-Wye festival in Wales, when the helicopter begin to veer - or yaw - to the right as it approached Denham aerodrome in Buckinghamshire.
The 53-year-old captain declared a Pan emergency, a less serious declaration than Mayday, and carried out a running landing at Denham.
It was described at the time by a royal source as "quite a hairy incident".
Prince Charles has been in South Wales today to celebrate anniversaries and achievements.
He started at the offices of the Abergavenny Chronicle meeting staff and celebrating the 125th anniversary of the Brecon and Radnor Express.
After then he visited Tredegar House to meet the mentors who have been helping the over fifties get back into work. He finished the day at the Ewenny Priory.
Megan Boot reports.
Prince Charles' pre-Christmas visit to Wales is concluding with a tour to Ewenny Priory, near Bridgend.
The priory is the most complete Norman church in South Wales.
This is the first royal visit for 600 years.
The Prince of Wales will help celebrate the 125th anniversary of a local newspaper during a day-long visit to Wales later.
He begins in Abergavenny meeting staff at the local newspaper and marking a milestone anniversary of a sister publication, the Brecon and Radnor Express.
Later he is due to visit historic Tredegar House, near Newport, and attend a reception for one of his charities.
PRIME Cymru, the Prince's Initiative for Mature Enterprise in Wales, and supporters will be attending a celebration of its Enterprise Mentoring programme.
The Prince's pre-Christmas visit to Wales concludes in the afternoon with a tour to Ewenny Priory, near Bridgend.
The priory is the most complete Norman church in South Wales, and remains at the centre of a thriving Christian community.
Before leaving the church, the Prince will listen to carols sung by children from the choir of St Brides Major Church in Wales Primary School.
Prince Charles said he has "nothing but the happiest and fondest memories" of Nelson Mandela and that the world "will be a poorer place without him".
The Prince of Wales smiled as he recalled meeting Mandela in South Africa with the Spice Girls, which he said was "very enjoyable".
"We owe him an enormous debt of gratitude for what he's managed to achieve in his life", he added.
The Prince of Wales has guest edited Country Life to celebrate his 65th birthday tomorrow.
Charles's birthday falls on the eve of the start of the Commonwealth Heads of Government Meeting (Chogm) he will host in Sri Lanka.
It will be one of his most significant duties to date as a future monarch but the summit has been overshadowed with controversy over the country's human rights record.
He used his editorial to voice his support for farmers, saying they were not getting paid enough by big supermarkets. He said:
"It cannot be right that a typical hill farmer earns just £12,500, with some surviving on as little as £8,000 a year, whilst the big retailers and their shareholders do so much better out of the deal, having taken none of the risk."
Prince George has been given a Welsh gift - a tree planted in his honour.
Prince William will be given a certificate today by First Minister Carwyn Jones later to mark the gift which will be planted in Llyn Geirionydd near Llanrwst.
A tree has been planted for every child born or adopted since 2007 but one has been planted for Prince George because of his parents time spent living on Anglesey.
The world's media has been focused on the christening of Prince George today. As King, he'll one day be Supreme Governor of the Church of England. But in Wales, christenings are becoming less popular, with the amount of services almost halving in the last 20 years. Alexandra Lodge reports.