HRH The Princess Royal will attend the birthday celebrations of Europe's biggest ram sale in Llanelwedd on Monday.

Princess Anne will visit the event at the Royal Welsh Showground where the first NSA Wales and Border Ram Sale was held in 1978.

Her Royal Highness has a keen interest in farming issues thanks to her work with rare breeds on her Gatcombe Park estate in Gloucestershire and her visit to Powys marks the sale's pivotal role in developing key sheep breeds in Britian on its 40th anniversary year.

HRH The Queen Mother, Princess Anne's grandmother, was an early supporter and took a personal interest in the sale and sent her North Country Cheviots all the way down to Mid Wales from her Royal residence Castle of Mey on the northern tip of Scotland.

Since 1978, the sale has grown from 660 rams when Suffolks were the dominant breed to as many as 11,000 rams from 33 different breeds and sold in 22 rings when the sale was at its peak. The sale also has an annual turnover of £2.5 million.

The all time record price of 18,000 guineas was achieved by Tywyn breader Llion Jones’s shearling Texel, Pant Wolf.

The first pure bred Texel ram sold in Wales was in Builth for 800 guineas to the late Lord Hooson.

The NSA Wales and Border Ram Sale was the brainchild of the late Verney Pugh OBE, who spotted the need for a multi-breed ram sale south of Kelso in Scotland and was masterminded by the committee chair of 32 years, the late George Hughes MBE.

The multi-breed ram sale's reputation is known worldwide for its quality, with each tup individually inspected by a team trained by the sale vet, which was first introduced by Montgomery vet Terry Boundy.

A spokesperson said: "It is a huge economic driver in Mid Wales and the emphasis on quality and veterinary inspection has helped to improve standards throughout the sheep industry."

"The sale also made it easier for farmers to experiment as the late 1970s and 1980s saw the emergence of the continental breeds, without them having to make the long trip to Scotland. They could buy a Texel or a Charollais along with the then dominant Suffolk as a terminal sire.

"It is of significant economic importance in Mid Wales, also bringing trade to hotels, guest houses and ancillary businesses during the run up to the sale."