The Prince of Wales in numbers

The Prince of Wales meets exhibitors during his visit to the Westmorland County Show in Milnthorpe, Cumbria Credit: Owen Humphreys/PA

Prince Charles turns 70 this week and is the longest serving Prince of Wales in British history.

He has been Heir to the Throne since his mother became Queen in 1952 and was officially made Prince of Wales in an investiture in Caernarfon in 1969.

Here’s a look at the Prince of Wales in numbers ahead of his birthday:

1 – Place in line to the throne.

2 – Sons – the Duke of Cambridge and the Duke of Sussex.

3 – Age when he became heir to the throne.

Prince Charles, in the year he became heir to the throne, with sister Princess Anne Credit: PA

3 - Grandchildren – Prince George, Princess Charlotte and Prince Louis – becoming 4 after the Duke and Duchess of Sussex’s baby is born next spring.

5 - Step-grandchildren – the Duchess of Cornwall has five grandchildren: Lola and Freddie Parker Bowles and twins Gus and Louis Lopes, and their sister Eliza.

9 - Age when he was given the title the Prince of Wales by the Queen.

11 - Years married to the Princess of Wales before they separated.

13 - Years married to Camilla.

The Prince of Wales and the Duchess of Cornwall at Royal Ascot. Credit: Adam Davy/PA

15 - Years married to Diana, Princess of Wales, before they divorced.

20 - Age at his investiture as the Prince of Wales at Caernarfon Castle in 1969.

21 - Charles is the 21st Prince of Wales and the first since 1936.

The Prince of Wales’s investiture at Caernarfon Castle in 1969. Credit: PA

32 - Age when he married 20-year-old Lady Diana Spencer in 1981.

44 - Commonwealth countries Charles has visited out of the 53 Commonwealth nations.

56 - Age when he married Camilla Parker Bowles in 2005.

After a few lessons, Charles soon had the dance moves memorised on his latest Royal tour in West Africa. Credit: PA

More than 420 - Charities of which the prince is patron or president.

875,000 - Disadvantaged young people helped into employment or business by his youth charity, the Prince’s Trust.

£141,263 - Cost of seven royal train trips, costing more than £20,000 each, in 2017-18.

Charles is greeted with a hongi by Grant Hawke during a welcome ceremony at Auckland War Memorial Museum in 2012. Credit: PA

£140 million - Money raised by his charities each year.

£45.7 million - Taxpayer funds received by the monarchy to pay for official duties and other expenditure in 2017-18.