Mike Catt was almost exactly 35½ when he led England against Wales in Cardiff 11 years ago, an age which the ageless Ulsterman eclipsed between the second and third stages of the emerald Slam.

Best, of course, can cite others renowned for their longevity and claim that he is but a spring chicken by comparison, a Rory-come-lately.

Simon Shaw, the England and Lions second row, was still playing in the Six Nations at nearer 38 than 37, against Ireland in Dublin seven years ago.

Victor Matfield captained the Springboks during the last World Cup at 38. The Argentinian hooker Mario Ledesma had been almost exactly the same age as the venerable Springbok during the previous World Cup in New Zealand four years earlier.

Mark Williams, an American Eagle from the previous century, still holds the distinction of being the first, and last, 38-year- old back to appear at a World Cup, coincidentally against

Ireland at Lansdowne Road in the autumn of 1999.

It happened so long ago that Williams was marking a 20-year-old fresh out of Blackrock College, Brian O’Driscoll.

The daddy of them all appeared at the same World Cup, the Uruguayan No. 8 Diego Ormaechea at the age of 40.

More recently, one of Best’s front row props, the Leinster tighthead Mike Ross, was in his 37th year when he bowed out in South Africa two years ago to make way for the phenomenal Tadhg Furlong.

Best’s contract extension is no more than he deserves, due reward for his success since inheriting the role of on-field general since a hamstrung Paul O’Connell limped into

retirement three years ago.

Since then Best has led Ireland to victory over every major opponent on each side of the equator — New Zealand, South Africa, Australia, Argentina, England, France, Italy, Scotland, Wales.

While he would be the first to give the credit for that to those under his leadership, there can be no denying that nobody in Europe is currently standing the test of time quite like the durable Ulsterman.

That said, it will still require a monumental effort even for a man of Best’s indestructible will-to-win to stretch his longevity through to a fourth World Cup.

Joe Schmidt may joke about his captain going “faster and faster on the zimmer frame” but his regime takes a ruthless attitude if anyone falls short.

Success brings its own penalties. As undisputed champions of Europe, Ireland will go to Australia in June in the unusual position of being expected to win the three-Test series against the Wallabies.

The merciless treadmill offers no escape. After Australia, the autumn series brings the ultimate challenge as presented by the All Blacks.

Clocking up 40 points against them in Chicago is one thing, edging them in Dublin by one point has been beyond every Irish team since the beginning of time.

As if that’s not demanding enough, there will be the small matter of defending the Grand Slam next year long before the World Cup bandwagon heads off for its first oriental jamboree.

Nobody would insult Best by questioning the desire and hunger of a captain who will be acutely aware of how Ireland has sold itself seriously short at every World Cup from the cringing, haphazard beginning at Wellington in 1987 when they lined up against Wales to hear The Rose of Tralee come crackling over the tannoy as a makeshift anthem.

Back-to-back Slams are so rare, they have only been done twice since the end of the Second World War.

Will Carling’s England did it first, overpowering a poor Wales team in a one-sided finale at Twickenham in 1992, 12 months after edging a thriller against France at the same venue.

Having outplayed their opponents 3-1 on tries, including the greatest seen at ‘HQ’ as started by Pierre Berbizier behind his own goalposts, France did their own double Grand Slam, routing Wales 51-0 with a seven-try exhibition every bit as scorching as the weather.

They, too, did it under the leadership of a hooker, Raphael Ibanez whose grandfather had taken refuge on the far side of the Pyrenees after the Spanish Civil War.

‘Rafa’ lasted another 10 years only to be drummed out two Tests short of a century after France failed to reach the final of their own World Cup in 2007.

Best has been around far too long to fall into the trap of looking beyond the next game, Ulster against Cardiff Blues at the Arms Park this afternoon.