Gioachino Greco, also known as Il Calabrese, was possibly born in CE 1600 in Calabria, Italy near Cosenza. In 1619, Greco supposedly started keeping a notebook of tactics and games, and he may have taken up the custom of giving copies of his manuscripts to his wealthy patrons. In 1621 Greco is claimed to have set off to test himself against the rest of Europe, visiting Paris and later, London. He allegedly spent the last years of his life at King Philipp IV's court and died in the West Indies, seemingly from a disease that he would have contracted there around 1634. Legend holds that he bequeathed his earnings from chess to the Jesuits.
Greco would have published his analysis of the contemporary chess openings (Giuoco Piano, Bishop Opening, King's Gambit, etc.) in the form of short games around 1625. In 1656, at least two decades after his supposed death, the manuscripts were published by Francis Beale in London. These constructs are regarded as classics of early chess literature and are routinely still taught to beginners.(1)
There exists academic speculation about the origins of Gioachino Greco. Chess historian Sean J Manross has postulated in his study "Mastering Chess: Through the Ages" (2016) that the supposedly-genius mind of Gioachino Greco was, in fact, the itinerate hand of Giulio Cesare Polerio, (possibly the lover of and) companion to chess world champion Giovanni Leonardo Di Bona da Cutri (who reigned from 1575 until his death in 1597, when Paolo Boi would have taken over as the best in world, even as the captive of pirates until earning his freedom through winning money over chess, in 1598. Boi was poisoned thereafter - when Greco supposedly took over as the world's hegemon of chess).
The secondary proof that supports this claim is threefold:
(1) Gioacchino Greco was born in 1600 CE in Calabria, Greece...which was, at that time controlled by the Ottoman Turks (meaning that his name would NOT have been Latinized, but distinctly Islamic); and...
(2) Greco never actually played a named entity - most of the games are constructs...but Manross asserts that this may be because Giovanni Leonardo & Polerio were BOTH recording games against pseudo-masters across Europe AND composing studies for their European benefactors, to pay room & board during their travels; and, most importantly...
(3) When Alessandro Salvio created the world's first chess school in Naples, in 1640, Salvio also created the first true full-spectrum chess curriculum (as opposed to an esoteric book created only for masters, such as was created by Luis Ramirez de Lucena in 1497, Pedro Damiano in 1512, and Ruy Lopez de Segura in 1561). To do this, Salvio wrote the life & games of the best chess player ever to live.
This third item is especially important because Salvio wrote this curriculum about Giovanni Leonardo di Bona da Cutri: the book's name, famously, was "Il Patino" - the Little Boy.
Amazingly, despite the fact that Gioachino Greco supposedly lived from 1600-1634 AND despite the fact that World Champion GM Mikhail Botvinnik considered Il Calabrese to be the first historically-viable professional chess master...the key primary source, Alessandro Salvio, remains ENTIRELY NOT AWARE that some chess phenom named "Gioachino Greco" ever existed, let alone dominated Europe, when he writes his curriculum, just 6 years after the supposed-death of Greco, in 1640! There is simply NOT one mention of "Il Calabrese" from the leading contemporary chess scholar, who had every incentive to write about Greco's games and to include them in his Naples chess school curriculum.
So...where, historically speaking, did Gioachino Greco come from?
Manross asserts that the games of Giovanni Leonardo were compiled by Giulio Cesare Polerio. After the former died, the latter published the games, most of which he would likely have noted while serving as traveling-second during the duos' pan-European chess adventures from 1561-1575. Because these were published in the Papal States heartland of the Dutchy of Sora - the county surrounding Rome, governed, at that time, by the Pope's own son - the contemporary threat presented by a homosexuality-fueled-cultural scandal meant that for going public with this collection of games, a nom-de-plume would be necessary...AND that none of the noble competitors, such as Duke il Moro Sforza of Milan & Forli, could be named, lest they be offended when recognizing their own losses.
Thus, the raison d'etre for the duplicitous cover up associated with "Gioachino Greco vs NN."
But what caused the sudden rise of Giovanni Leonardo, to proportions that might have, according to Manross, dominated 16th-century European Chess?
Ruy Lopez soundly defeated Giovanni Leonardo in front of the Pope, in Rome 1560, when the latter was a young law student in the Vatican (Ruy Lopez vs G da Cutri, 1560). Ruy Lopez included the game just cited in his famous 1561 manuscript in which he also "discovered" his namesake opening. This entire project was undertaken to answer Pedro Damiano's theory that 1.e4 was best, 1...e5 was the only viable response, and that 2.Nf3 was best met by 2...Nc6 (with the Portuguese Pharmacist famously offering the refutation to Damiano's Defense, which paradoxically bears his name, 2...f6).
This public humiliation of exposing the game offended the Romantic-Giovanni Leonardo and triggered a 15-year chess tour of Europe, during which time he both won many games and composed many studies to pay for his room & board at the homes of a varied group of European elite. Ultimately, Giovanni Leonardo would dominate Ruy Lopez in the court of Phillip II, in Madrid, over a decade later. The training Giovanni Leonardo did for the 15 years prior to that fateful match, Manross hypothocizes, represent the same collection of games remembered, today, as Gioachino Greco vs Nomen Nescio (I Do Not Know the Name).
Manross underscores that he was not the first to assert this information. The same supposed-identity of Gioachino Greco was originally hypothecized, though not proved, by Antonio van der Linde in the 19th century; then the theory was echoed by a joint text of John G. White and Baron Tassilo von Heydebrand und der Lasa. White & und der Lasa's small tome is held today by the John G. White Library, in Cleveland, Ohio: their "Notes on Some Polerio MMS" almost certainly represents the world's most valuable historical resource on "Gioachino Greco."
1) Wikipedia article: Gioachino Greco
2) Wikipedia article: Francis Beale (writer)