A Suffolk charity dedicated to preserving the county’s rare horse breed is today celebrating its own Royal birth.

As the Duke and Duchess of Cambridge prepare to welcome a second child, news has reached the Suffolk Horse Society (SHS) that the Princess Royal’s home-bred mare has produced her first foal.

It’s the second piece of good news for the charity, which is set to compile a treasure trove of archives charting the history of Suffolk’s heavy horse, thanks to a lottery grant worth £85,000.

A patron and honorary member of the SHS, the Princess Royal is a noted admirer of the heavy horse. In 2010, she visited the Suffolk Punch Trust at Hollesley, opening the £2 million project’s new education and heritage visitor centre.

Her Royal Highness has now helped safeguard the breed, after her Suffolk mare, Tinglestone Summer Breeze – known as Windy – produced a “fine, strapping” colt sired by Euston Malachite, owned and bred by SHS vice patron, the Lord Lieutenant of Suffolk, Clare, Countess of Euston.

Both mare and foal are now back at Gatcombe Park, the Princess Royal’s country residence.

SHS chairman, George Paul believes that, with such prestigious champions, the breed can only go from strength to strength.

He said: “It’s wonderful that the foal should be from a stallion of the Lord Lieutenant of Suffolk.

“Numbers have been up and down but we now have in excess of 500 horses.

“For one reason or another, many don’t breed – they may be geldings or old mares. The key is how many foals we produce. The year before last it was 50, last year it was 35. We wouldn’t like to see that fall below 30.”

The Rare Breeds Survival Trust currently rates the Suffolk horse as ‘critically endangered’. SHS offers grants to owners who are willing to breed their horses.

The society, founded in 1877, has just received an £85,000 grant from the Heritage Lottery Fund to catalogue, and make available for reference and research, its extensive archive.

The project, which has the working title ‘Tracing the Future: Exploring the Heritage of the Suffolk Punch’, will follow ‘Working Horses, Working Lives: Sharing our Stories of the Suffolk Punch’. Together, the two projects will provide an oral, written and photographic record of the horse and its place in rural history.

Mr Paul said the archive included a handwritten letter, dated 1934, from the first Baron Daresbury, Gilbert Greenall, the director of the Royal Agricultural Show, requesting that when the event arrived in Ipswich, organisers made a special effort because The King was coming.