Christopher Columbus was born in Cuba - at least that's what they say in the village of that name south-east of Lisbon in the heart of Portugal's Alentejo region. Portugal's first statue of the explorer is to be unveiled in Cuba's central square on Saturday, the 514th anniversary of Columbus's landfall on the Caribbean island later named after his supposed birthplace.
The 7ft bronze monument, showing the Admiralbestriding the globe, rolled map in one hand, shading his eyes with the other, will stand upon a granite pedestal facing Cuba's ancient palace of Duke Fernando of Beja, of whom, so the theory goes, Cristovao Colom was the illegitimate son.
The ceremony, to be attended by Portugal's Culture Minister, Isabel Pires de Lima, will strengthen the arguments of Portuguese historians that the voyager who first set foot in the Americas was neither Genoese, as is generally thought, nor Catalan - as a counter lobby insists - but Portuguese, of mixed noble and Jewish blood.
The mystery of why Columbus apparently covered up his Portuguese roots - even though he spoke the language fluently - is explained by the possibility that he was secretly working as a double agent for the Portuguese King Joao II, while accepting riches to fund his transatlantic voyages of discovery from Queen Isabella and King Ferdinand of Spain - Portugal's bitterest rivals in the conquest of America.
Cuban locals recall hearing tales dating from the early 1900s that he was baptised in the village church. But the first serious research was published by the Portuguese historian Mascarenas Barreto in his 1988 book, Cristovao Colom, agente secreto do rei Dom Joao II. Barreto hypothesised that the explorer was really Salvador Fernandez Zarco, who assumed the pseudonym Cristovao Colom to present himself to the Spanish royal court.
A year after Barreto published his study, a US scholar Manuel Luciano de Silva joined the trail. How, the two historians asked, could a man said to have come from a humble family of Genoese weavers move in courtly circles, and marry a noblewoman? Why did a young Genoese who left his home town at 24 express himself only in Spanish, or Portuguese, even when writing to his Genoese friends? Why did he name none of his discoveries in the New World after Italian places, whilst peppering the region with Portuguese place names like Veracruz, Santo Domingo - and Cuba?
Salvador Fernandez Zarco was the son of Isabel Gonsalves Zarco, daughter of the Jewish Portuguese navigator Joao Gonsalves Zarco, the discoverer of the Atlantic island of Porto Santo, near Madeira. Dom Fernando Duque de Beja had an illegitimate son with Isabel. She gave birth to Salvador at the duke's palace in Cuba - 12km north of the town of Beja - in 1448. When the boy was six he travelled with her to Porto Santo, and at 14 began his career as a seaman and navigator.
Christopher Columbus married Filipa Perestrello e Moniz, the daughter of Madeira's governor, in 1479 - an achievement Portuguese historians consider impossible unless he was himself of noble birth - and she bore his first son, Diego.
Da Silva and Barreto reckon Columbus never revealed his true identity because the Duke of Beja was a mortal enemy of King Joao II, who had ordered Fernando's assassination. This apparently explains why the duke's natural son Columbus hastened to Spain, and refused King Joao's written invitation to return, in a letter guaranteeing that Columbus would suffer no harm.
Historians point to the curious fact that when Columbus returned from his first voyage of discovery he landed first in Lisbon and, armed with that letter, sought an audience with "his" king.
He spent a week in the Portuguese royal palace before sailing to Spain to report to the monarchs of the discoveries that they had financed.
The Portuguese historian Joaquin Verissimo believes Columbus secretly served the monarchs of both Spain and Portugal.
Today's claimant to the Portuguese throne, Dom Duarte de Braganza, direct descendent of Duke Fernando, has donated a blood sample to the Spanish and Portuguese governments in the hope his DNA can be matched with that of Columbus or his descendants.
Who was Columbus?
Spaniards call him Cristobal Colon, Italians Cristoforo Colombo, Catalans Cristofol Colom. Whatever his real name, the explorer who sailed the ocean blue to discover America in 1492 was either Catalan, Spanish or Portuguese depending on which rival historian you ask.
Usually said to have been born of a humble family in Genoa in 1451, he made three more journeys after his first, momentous voyage, all funded by the Spanish crown, still believing he had reached Asia.
He opened the door to Spain's conquest of the Americas. He died on 20 May 1506 in Valladolid, Spain. His remains were taken to Seville's Carthusian monastery, then to the cathedral of Santo Domingo, at the request of his son Diego. They were later removed to Havana and, possibly, returned to Seville.
Only DNA testing can prove his origins and which bones in various graves are his.