It is a name that resounds down the ages. Merckx. Once it was only a word muttered in fear by a cyclist leading a stage who suddenly heard the whirring of wheels and was passed in an instant. Merckx. The cyclist who changed everything, who showed all was possible. Merckx.

The Belgian dominated an era and his reputation has seeped into the consciousness of every serious cyclist since the dark-haired and quiet son of a grocer changed the landscape of the sport with a series of performances that dismayed, even demoralised, his rivals.

His greatest year was 1969 and a new book captures it in photographs and words. One of its creators is Jan Maes, who once gazed upon the wonder of Eddy Merckx and was smitten for life.

Maes does not deal in the prosaic. But the statistics of the professional life of Merckx demand to be stated. Born in June 1945, Merckx won 525 races, including five Tours de France, five Giri d'Italia, and a Vuelta a Espana. His record in the classic one-day races was astonishing.

He arrived in 1969 with that whirring of wheels and an avaricious appetite that devoured his opponents, causing him to be nicknamed the Cannibal. They felt his breath on his neck and they winced, waiting for the Cannibal to strike. In 1969, Merckx won the Tour de France, the Paris-Nice, Milan-San Remo, Tour of Flanders, Liege-Bastogne-Liege. In 1969, he won the general classification, the time trial classification, the sprint classification and the mountain classification in the Tour de France. In 1969, he was almost killed in an awful crash at Blois. Ferdnand Wambst, directly in front of him, died. In 1969, Merckx failed a drug test in Savona and so left the Giro d'Italia.

Savona and Blois would remain forever in the Merckx psyche. He always believed he had been a victim of a conspiracy at Savona, though he failed two other tests in his career.

The consensus, however, is that his supremacy owed nothing to drugs. He did not use anything his opponents did not have access to and even his enemies insist that the Belgian was the best through a natural talent and superhuman will.

The fall at Blois, though, left a physical mark. His injuries meant that Merckx was never quite the same though still invincible into the mid-seventies.

Maes is linked to his hero by a romantic story. "The first memory that I have is his victory on the Mont Ventoux at the Tour de France of 1970. He rode all the opponents into the dust but a few moments later he lost his consciousness. I will never forget that moment, it will be always on my mind. That's the beginning of my adoration for the cyclist," he said. His first book on the cyclist, Merckxissimo, celebrated the 40th anniversary of the 1969 win in the Tour de France.

Now Merckx, written by Maes with photographs by Tonny Strouken, captures a remarkable year for history. "The way he won was bigger than the victory itself. Next to all these victories, next to all the glorious moments, 1969 could also have been the end of his career and even his life. Two moments show the dark side of life: the drama of Savona and the fall in Blois. 1969 was a total story," said Maes.

In the 1969 Tour de France there were great days, including a stage where Merckx almost routinely gave an intimation of the greatness that was to be insuperable in an extraordinary era.

"The biggest performance was the stage from Luchon to Mourenx-Ville-Nouvelle. He did things that had never been done before," said Maes of the ride that saw Merckx finish eight minutes clear after cycling alone for 140km. The Belgian was regularly applauded that year by other team managers on the side of the road but this was his most dominant performance.

"When you can do such things, you have realised the highest level of your sport," he said. "But however great the performance was, I think that the greatest day in 1969 for Eddy was the arrival at the velodrome in Paris. Thousands of supporters were there, his wife was there and his mother was there. He came home, he won the biggest race on earth. But I think the most important thing for Eddy was that he took revenge for his exclusion of Savona in the Tour of Italy. He showed everyone that he didn't need dope to be the best. He succeeded in his mission."

The annus mirabilis of 1969 remains unchallenged by any other cyclist in any other era.

"Each generation has his own heroes and life is constantly in evolution. But I believe that it will be impossible to dominate the same way as Eddy Merckx has done.

"I must remark that he was, without any discussion, the best of his generation. His generation was also one of the strongest that we ever had in cycling. Names such as Raymond Poulidor, Felice Gimondi, Luis Ocana, Jose Manuel Fuente, Roger De Vlaeminck, Herman Vanspringel, Walter Godefroot, Lucien Van Impe, Joop Zoetemelk, etc. I can immediately give more than 20 great champions. They had all one purpose: beat Eddy Merckx. Even a conspiracy of power was not enough to do that. This shows what a team-mate of Eddy, Patrick Sercu, has said: 'You can only know the strength of Merckx when you had the opportunity to ride against him'."

Maes believes with reason that Merckx is incomparable.

"He is the greatest cyclist of all time. I compare him with the highest level a sportsman can reach. His level was a level of superiority. You can compare Merckx with men as Ali, Pele, Ayrton Senna, Bjorn Borg, Michael Jordan or Carl Lewis.

"All these people are icons. You must be very carefully with the word icon. You can count real icons on the fingers of two hands. Not more than that. Why is Merckx one of them? Because he has given a new dimension to his sport. He has done things that no one ever did before. He brought his greatest enemies to admiration. He never rode to make his opponents lose, he always rode to win for himself, to win for the beauty of his own sport."

Merckx was in many ways a simple personality, certainly off the bike.

"His honesty and friendship," answered Maes when asked about the personal qualities of his hero. "Eddy often rides with his former team-mates and after the ride, everyone is invited at his home. It's not easy to become close to him, but once you've proven that your intentions are pure and that you're worth the trust, the relationship becomes very close."

But what, apart from his physical power and his talent, set Merckx apart? "The greatest trait of Merckx was the passion for his job. He was an artist on his bike. I admire his consciousness of duty. Doing something for the full 100%, even when you know you're the best.

"I admire his unconditional love and his perseverance for his job. For me, that's the secret of a great sportsman," said Maes.

Merckx 69: Celebrating the World's Greatest Cyclists in his Finest Year, written by Jan Maes and Tonny Strouken, is published by Bloomsbury Sport and available for £35