The manner in which they emerged victorious simply added to their legend, with power and pace, quick feet and even quicker hands at the heart of a truly wonderful achievement.
Those traits were nowhere more evident than in the third-Test win in Wellington as the Lions bounced back from disappointment to produce a commanding display that ensured they would leave New Zealand with at least a share of the series regardless of what ensued in the final rubber.
NEW ZEALAND 3 BRITISH & IRISH LIONS 13
Half-time: 0-13 Venue: Athletic Park, Wellington Attendance: 50,000
Scorers: New Zealand:Try - Mains; Lions: Try - TGR Davies, John; Con - John; Drop goal - John
SETTING THE SCENE
The series ended with a mesmerising 14-14 draw in Auckland and it is that match that is so often brought to the fore when the class of '71 form the topic of conversation. But while the fourth Test ultimately secured the series, it was the third international that really did the damage as far as the All Blacks were concerned.
The Test series had begun with a shock 9-3 success for the tourists at Carisbrook - a shock for the Kiwis that is - but the All Blacks retaliated in fine fashion to win the second Test 22-12 in Christchurch.
With the series now level at one-apiece and the All Blacks apparently in the ascendancy, the New Zealand press only saw one winner. The Lions' victory in the opening rubber had been a one off they said; that success wouldn't be repeated they wrote; the Lions would be valiant but not victorious from now on in.
How wrong they were. The Lions bounced back from the convincing Canterbury defeat in stunning fashion as they set the platform for their crowning moment a fortnight later.
Both sides made two changes from the second Test, although there was one key difference: the Lions brought in two new men out of choice while the All Blacks' alterations were forced upon them.
The hosts actually named the same team that had triumphed in the second international but injury meant they had to call up a replacement in the backline and one in the pack.
Wing Brian Williams, a try scorer in Christchurch, was replaced by his Auckland club-mate Ken Carrington who had started the first international five weeks earlier, while lock Peter Whiting's place was taken by Brian Lochore.
The second of those switches was a major talking point prior to the match, with ex-skipper and legendary Kiwi Lochore a surprise inclusion. There was no doubt the Wairarapa Bush veteran would forever be considered an All Black great but critics believed he was well past an international recall.
For the Lions, their own changes in personnel were purely tactical, even if one of the outgoing players had picked up a knock in the second Test.
England flanker Peter Dixon had suffered a nasty blow to the head in the 22-12 reverse and had perhaps understandably failed to get a grip on inspirational All Black scrum-half Sid Going. That led James to draft in Derek Quinnell, a player who he had under his guidance on a daily basis as coach of Llanelli.
Quinnell was the only uncapped member of the touring party but had impressed throughout and fully deserved his call up. The young Welshman was charged with keeping a close eye on Going and he did just that, disrupting the All Blacks' flow and helping Edwards win the battle of the world's two best No9s.
Derek Quinnell replaced Peter Dixon at blindside flanker
The second change made by James and tour manager Doug Smith came in the pack. Whereas the All Blacks drafted in a second row clearly at the end of his international career, the Lions opted for one who was only just starting his.
Gordon Brown may have made his Scotland bow two years earlier but this was his first appearance for the Lions. The affable giant, who sadly died of cancer in 2001, would go on to establish himself as his country's greatest-ever second row, playing in eight Tests for the Lions and tasting series success on two occasions.
Brown came in for the far more experienced Delme Thomas who had started the first two Tests and would come on as a replacement in the fourth and final encounter.
Elsewhere, the Lions kept faith with their starting XV despite defeat in the second rubber. Although they had lost out convincingly at Lancaster Park, many of the Lions themselves believed they had played better that day than in the first Test in Dunedin.
Just like in the first and second internationals, the Lions side was dominated by Welshmen, with five backs and three forwards hailing from coach James' home country.
England's David Duckham and Ireland's Mike Gibson were the exceptions in a star-studded back division described by most as the deadliest ever produced by a British and Irish side. With Gareth Edwards and Barry 'The King' John at halfback, Gerald Davies and JPR Williams out wide and at the back, and skipper John Dawes solidifying the midfield, this batch of Lions backs really were something special.
But while the speedsters and sidesteppers received most of the acclaim, the forward pack were far from pushovers. Scotland's Ian McLauchlan, Ireland's Sean Lynch and England's John Pullin provided a stable platform up front despite being written off as no match for a powerful All Black front row - a real surprise to the Kiwi public who hadn't fancied the Lions' chances even before first-choice props Ray McLoughlin and Sandy Carmichael were punched out of the tour prior to the first Test.
Lions legend Willie-John McBride provided some real steel alongside Brown in the boilerhouse, with Quinnell completing an all-Welsh back row that also featured livewire openside John Taylor and celebrated No8 Mervyn Davies, both of London Welsh and both ever-presents throughout all four Tests.
Lions regulars Mervyn Davies and JPR Williams had plenty to smile about
New Zealand: L Mains; K Carrington, H Joseph, B Hunter, W Cottrell; R Burgess, S Going; R Guy, T Norton, J Muller, B Lochore, C Meads (captain), I Kirkpatrick, A Wylie, A McNaughton
British & Irish Lions: JPR Williams (London Welsh/Wales); Gerald Davies (London Welsh/Wales), John Dawes (London Welsh/Wales, captain), Mike Gibson (NIFC/Ireland), David Duckham (Coventry/England); Barry John (Cardiff/Wales), Gareth Edwards (Cardiff/Wales); Ian McLauchlan (Jordanhill/Scotland), John Pullin (Bristol/England), Sean Lynch (St Mary's College/Ireland), Willie John McBride (Ballymena/Ireland), Gordon Brown (West of Scotland/Scotland), Derek Quinnell (Llanelli/Wales), John Taylor (London Welsh/Wales), Mervyn Davies (London Welsh/Wales)
Referee: John Pring (Auckland, New Zealand)
The Lions produced a superb first-half performance at Athletic Park as they made good use of a decent tail wind.
The tourists raced into a 13-0 lead that the All Blacks never truly looked like over turning.
John started the surge with a third-minute drop goal before his half back partner Edwards conjured up two moments of magic to create a brace of early scores.
The world's greatest scrum-half first made a blindside break to put Gerald Davies over in the corner for a try that John converted with the help of an upright.
Edwards was at it again shortly after his initial burst of inspiration as he showed his pace, power and precision to create a second score for John.
The Wales No9, playing in the fifth of his 10 Tests for the Lions, broke past the tail of a lineout, handed off a New Zealand defender and then released a perfectly-timed pass for his Cardiff team-mate to race over.
Again John converted and the Lions were as good as home and dry before the half-time whistle.
The All Blacks threw everything they had at the Lions in the second period but Dawes and his troops never buckled. They remained organised in defence, stuck together as one and tackled like demons to restrict the All Blacks to just a single score.
That score came courtesy of full back Laurie Mains 10 minutes after the interval but it was as close as the hosts got to clawing back the Lions' lead.
Gerald Davies scored the first of the Lions' two tries
THE LIONS IN WELLINGTON
The Lions have played 29 fixtures in Wellington, with the city featuring as a venue on every single one of the Lions' 12 tours to New Zealand.
Just over a third of those matches have been Tests, with the Lions winning only twice in 11 attempts against the All Blacks in the nation's capital.
The third-Test win in 1971 has only been matched by the 1993 Lions who won the second international in a 2-1 series defeat.
The Lions' last outing is a prime example of how difficult the tourists have found it to face New Zealand in The Windy City, with Sir Clive Woodward's men being hammered 48-18 in 2005. '1 '
P 29 W 16 L 11 D 2
1888: Wellington 3 Lions 3
H Roberts XV 1 Lions 4
1904: New Zealand 9 Lions 0
1908: Wellington 19 Lions 13
New Zealand 3 Lions 3
1930: Wellington 12 Lions 8
NZ Maori 13 Lions 19
New Zealand 22 Lions 8
1950: Wellington 6 Lions 12
New Zealand 6 Lions 3
NZ Maori 9 Lions 14
1959: Wellington 6 Lions 21
New Zealand 11 Lions 8
NZ Juniors 9 Lions 29
1966: Wellington 20 Lions 6
New Zealand 16 Lions 12
NZ Juniors 3 Lions 9
1971: Wellington 9 Lions 47
NZ Universities 6 Lions 27
New Zealand 3 Lions 13
1977: New Zealand 16 Lions 12
Wellington 6 Lions 13
NZ Juniors 9 Lions 19
1983: Wellington 19 Lions 27
New Zealand 9 Lions 0
1993: NZ Maori 20 Lions 24
New Zealand 7 Lions 20
2005: Wellington 6 Lions 23
New Zealand 48 Lions 18