If just a few words were used to describe Alastair Cook in his role as England's captain, "honesty", "integrity" and "resolve" might lead the way. In this age of unflagging self-promotion, he has remained private and discreet, whispering not a word of his own journey or, more particularly, of the hurdles that have made it more difficult and emotionally draining than anyone on the outside could possibly imagine.

On a personal level, he keeps clear of social media, but the general noise is unavoidable and he has frequently been aghast at the vitriol pumped his way. During the early part of the summer of 2014, when his team was losing matches it should not have, the freewheeling and generally irresponsible criticism all but finished him off. Somehow he found the strength to carry on, displaying perhaps the most impressive of his abilities - where he rolls up his sleeves and gets on with the job.

More recently in India, the signs that he would stand down of his own volition became clear enough. He dropped some catches that suggested both distraction and frustration, and was dismissed in ways that were too simplistic, even repetitive, for one with such an acute sense of survival. I don't suppose he will miss the captaincy for a minute - his was increasingly a sense of duty ahead of ambition. The heavy losses in India were insufferable, and for them he will have felt accountable. Actually he didn't stand a chance; the paucity of England's spin bowling is of great concern. Now he will worry less about such things and hope to turn up fresh of mind and body to do that which he does best: to clip either side of square leg and to clatter past point. He is a mere 4864 short of Sachin Tendulkar's 15,951 Test match runs, and betting against Cook has invariably proved to be a mistake.

My own experiences with him have been enormously worthwhile, whether in our official capacities or when more relaxed on private occasions or at charity events, say, where he gives more of himself than he needs to. His sharp wit keeps everyone on their toes, and that hugely competitive instinct is applied to the skills of fund-raising and dinner-party debate. For three consecutive years, he won Chance to Dine - a cooking reality evening to raise money for the promotion of the game in schools. He is no sort of a chef but was damned if any of his team-mates was going to lift even a cooking trophy ahead of him. He just finds a way. Much of his time is given to good causes, all of which benefit from his considerable presence, generous terms of engagement and keen interest in the event he is supporting.

It is well enough documented that his greatest triumph was to conquer India in 2012, where only Douglas Jardine, Tony Greig and David Gower before him had led England to success. The reintegration of Kevin Pietersen proved to be a master stroke, and the two of them batted as well, or better, than any visiting player to the land of parched pitches and voracious spinners. Twice he claimed the Ashes at home - only WG Grace and Mike Brearley have pulled that one off - but the ledger was redressed by the Australians down under in 2013-14, when the 5-0 scoreline neatly told the story of abject defeat. Such beatings take their toll. Having started out by winning in India, he finished by losing in India - 4-0 - and just the other day decided he had nothing left to give the job he came to enjoy more than he had imagined. Initially he was not "driven" by the thought of captaincy, but come closure he admitted to it being "an amazing job", "an incredible honour" and a commitment that requires 100% every day" - the sort of commitment he likes.

He believes that the game today is the equal of, or has improved upon, any other era in its history - an argument over which he cannot be swayed. Lillee and Thomson? Pah! Marshall and Garner? Huh! Try Johnson and Harris, or Steyn and Morkel

I once asked if he saw himself as ruthless. "Well, I like winning. I'm less concerned by the frills and more concerned with the result. Yes, I guess there is a ruthless element there somewhere. In time, people will look back and judge the days when I played as we all do those who played before us. I'd prefer that they talk about how we won Test matches instead of how we lost them. It's not complicated really - find a way to win."

One of the problems that faces the modern cricketer is the amount of time he spends analysing the game and his own performance. There was much to be said for knocking off the day job at 4 o'clock and heading to the nets before an early-evening beer and a yarn about the challenge ahead. Cook saw the dangers of this modern paralysis and created space between the business of bat and ball and interests elsewhere.

Nothing gives him greater pleasure than the family farm. Lambing, moving the sheep by hand, mucking out, working the dogs - this is the life that brings him the oxygen from which he breathes as an England cricketer. "In the end, playing for England means very little if you don't see the rest of the world around you. I suppose it is why I get so wound up by prima donnas and by arrogance. I like perspective and the farm gives you that. Whatever else, come rain or shine, the farmers meet for a beer at the local on a Friday evening. It signs off the week in a communal way that says we take care of our own." His two young children will grow up barely knowing the old man worked for more runs in an England shirt than anyone else. Instead, they will see the soil and sweat of the land. "Farming has shaped me," he says.

That may be so but 11,057 Test match runs tell us there was a bat in hand long before the shepherd's stick. It was in the back garden, where his brothers Adrian and Laurence aimed mainly at his head, that he learned the rudiments of survival: "I quickly found an instinct for staying at the wicket and have clung on to it ever since." Until the recent tour to India, that is, during which he admits to having been distracted from his own batting for the first time. Other issues crept up on him and invaded the precious space that had for so long remained clear and present. It will have been painful for him to step down but his batting will benefit from the release.

There is no reason why he should not play awhile yet, though the four or five years to which he referred on Tuesday seem extravagant. Fitness is on his side, mind you. The experts say that he is up there with any sportsman in the country and unbeatable at the bleep - or "yo-yo" - test. "True," he said with a smile. "I'm an endurance man, there are no fast-twitch fibres in my body. I'm unbeaten at the bleep in 12 years. Don't ask me for speed, ask me for endurance." Remind you of anything? Of course it does. Most of his innings.

When he passed the 10,000-run mark at Chester-le-Street last summer, he proudly raised his bat in the knowledge that he is one of only 12 men in the game's history to have celebrated such an achievement. He was openly delighted by this and chose not to hide it from the cameras. Given the generally vanilla relations between players and press these days, it was good to see his animation continue into the close-of-play interviews where he confessed immense self-satisfaction; for once rejoicing in his own achievement rather than attributing it to the greater whole of the team.

Of course he has been a stubborn so-and-so and naturally wary of intrusion. Part of this comes from his own reticence in front of camera or behind a microphone; the rest from his feeling that those in glass houses (press and commentary boxes) should be more careful with the stones they throw. He believes that the game today is the equal of, or has improved upon, any other era in its history - an argument over which he cannot be swayed. Lillee and Thomson? Pah! Marshall and Garner? Huh! Try Johnson and Harris, or Steyn and Morkel. It is one of the few points over which he and his long-time friend and mentor, Graham Gooch, vehemently disagree.

Almost certainly, Joe Root will want Cook alongside him - as much for the bloody-minded strength of character as anything else. Cook has plenty more to offer his successor, not least in the understanding of how best to come out of the blocks. Cricket captains have a limited time to build the team in their own image.

Cook started well but then stuttered in the face of the Pietersen affair and the retirement of key senior players. When stripped of the one-day captaincy and shocked into a realisation that the game - and specifically the more vibrant attitude of those now playing it - was passing him by, he adapted his approach to the job and found opportunity where previously there had been confusion. Taking something from Brendon McCullum's charm offensive and free spirit, Cook empowered his collection of younger cricketers and led them through the happiest period under his command. It is not easy to see how, on the back of it, eight Test matches were lost last year. Doubtless he could not unravel that problem either and the consequence of it is his abdication.

Sport moves so fast that one can rarely be sure of a legacy. Cook's love of cricket is almost enough in itself; that and the mountains of runs. But I shall think of his dignity under provocation and his kindness away from the spotlight. I shall remember his dazzling smile in moments of joy and his pain in moments of duress. We can sure there are more of these to come. Andrew Strauss says his old opening partner should be considered as one of the great England captains. There is loyalty and a long-term respect between the two of them in that view. For sure, he presided over great occasions - some of them against the odds. The men he now passes on have a strong moral code and a real sense of what is right and wrong in the world. It is a good place from which Root can build the next chapter in the long story of the England cricket team.

Mark Nicholas, the former Hampshire captain, presents the cricket on Channel Nine in Australia and Channel 5 in the UK