No more was heard of the 16th century author until the rediscovery of a novel featuring an eccentric character called Don Quixote rescued him from oblivion.
By then, nobody could remember where his grave was. Four centuries later, Spain intends to do the great man justice.
A team that will search for Cervantes's remains began exploratory work Monday and final conclusions — should the search succeed — will be known by the year's end. The estimated cost of the operation is 100,000 euros ($138,000).
A three-phase search will take place over some 200 square meters (240 sq. yards) at the Convent of the Barefoot Trinitarians in Madrid's historic Barrio de las Letras — or Literary Quarter.
When Cervantes moved to Spain's capital in 1606 he had already published the novel that was to change Spanish literature: "The Adventures of the Ingenious Nobleman Don Quixote of La Mancha."
Although his book enjoyed some success, it did not make him famous — and the author was better known in Spain as an ill-fated soldier.
Cervantes had been wounded in battle and spent years captive in Algiers. He had been seized by Turkish pirates who boarded the ship on which he was returning to Spain after fighting in a war against the Ottoman Empire.
The Trinitarian order negotiated his release and helped pay a ransom that ruined Cervantes' family.
Cervantes was compelled to live as an errand-runner for the convent to give thanks for his deliverance.
He lived in a neighborhood of narrow streets, small houses and taverns full of artists and hustlers, where wine flowed and tapas were served. Other authors of Spain's golden age of literature, such as Francisco de Quevedo, Lope de Vega and Luis de Gongora, ignored him.
He was buried in 1616 on his death at the age of 69. Years later the chapel was expanded to its current — still modest — proportions.
According to Fernando Prado, the historian in charge of the project, just five people, including a child and Cervantes, are buried there.
"We know he is buried there," Prado said. "History teaches us that churches never throw bones away. They might relocate them under roofs and vaults if necessary, but no one would dare throw them into a common ossuary."
The first phase will consist of exploration using radar. Excavation will begin if bones are detected.
"We will clearly see if there is altered terrain that will give us clues," said radar operator Luis Avial.
Avial's report will be ready in a month.
Then the investigation turns to Spanish forensic anthropologist Francisco Etxeberria, who participated in the autopsy that confirmed the suicide of former Chilean president Salvador Allende.
Forensic identification will be the last — and possibly most delicate — part of the process. Any bones found may have been mixed up. Prado said that with no living Cervantes descendants, DNA analysis is unlikely to lead anywhere.
The investigation will refer to the author's portraits and his own stories, in which he relates that shortly before dying he only had six teeth.
But the most obvious marks will be the battle wounds that Cervantes sustained. In 1571 the writer was wounded in the Battle of Lepanto, which pitted Ottoman Turkish forces against the Holy League, led by Spain. Aboard the ship La Marquesa, Cervantes was hit with three musket shots, two in the chest and one in his hand.
He spent several months in a hospital in Sicily, but managed to recover.
Although historic texts often speak of the "one-armed man of Lepanto," doctors never amputated his limb. He did, however, completely lose its use.
Should the bones be found, they will be returned to the church.
"He will be re-buried there, but with a plaque to remember his name and who he is," said Prado.