Daniel Bomberg, the first Christian merchant to found a Hebrew printing press, prints a Hebrew Bible with commentaries by Rashi, Ibn Ezra, Kimchi, Geronides and Babylonian and Palestinian Talmuds for the first time.

By 1524, the old established Jewish families of Rome has come to terms with the trasmontani: newcomers from France and Germany, who had previously not been accepted into Jewish leadership in Italy.

Roman Jewish self-government is now shared by Italian, Sicilian, Spanish and German Jews.

Rome, especially during the reigns of the Medici popes Leo X and Clement VII, who, remain sympathetic toward the Jews.

Jewish political activist David Reubeni, described by the Shengold Jewish Encyclopedia as "half-mystic, half-adventurer, "claiming to be a messenger of the king of the Lost Tribes, appears before Clement and proposes a treaty between Jews and Christians against Muslims.

Reubeni states that he was born around 1490 in a place referred to variously as Ḥabor or Khaybar, which will be subsequently identified with a place of a similar name in central Arabia.

He relates that he had been sent by his brother, King Joseph, who rules the kingdom with seventy elders, who is seeking alliances against the Turks conquering the area for its great wealth.

He had left Khaibar on December 8, 1522, traveled ten days' journey until he reached the port of Jedda, crossed the Red Sea, then disembarked from his boat in the city of Suakim in the country of the blacks.

He then joined a camel caravan which took him northbound, following the Nile River along the Nubian desert in northern Sudan, during which time he had disguised his identity by dressing as a Muslim and claiming to be a descendant of Muhammad.

This was done out of a concern for his own safety while traveling in a predominately Muslim country.

He eventually reached Cairo (where his Jewish host was reluctant to receive him in his house because of his Muslim appearance), Gaza, Hebron (where he visited the tomb of the Patriarchs) and Jerusalem.

When he spoke to audiences of Jews, he told of large Jewish kingdoms in the east, possibly referring to the Jewish community at Cochin or Yemen.

The Portuguese had just conquered Goa.

Another version is that his true origin was at a port called Cranganore, along the Malabar Coast of India, where a large and well-organized Jewish community had lived for many centuries.

Reubeni had traveled in the Ottoman Empire in the spring of 1523 and to Venice by way of Alexandria in February 1524.

In Venice he had reported to Clement VII, claiming to represent a mission from the Jews of the east.

He attracts funding from a Jewish painter named Mose, and Felice, a Jewish merchant for travel to Rome.

The same month Reubeni enters the city while riding a white horse.

Reubeni obtains an audience with Cardinal Giles of Viterbo and Pope Clement VII.

To the latter he tells a tale of a Jewish kingdom ruled over by his brother Joseph Reubeni in Arabia, where the sons of Moses dwell near the Sambation River.

He brings letters from Portuguese captains confirming his statements.

The Portuguese minister, Miguel da Silva, reports to his court that Reubeni might be useful in obtaining allies.

The Portuguese are competing against Selim I, who had seized Egypt in 1521 and diverted the valuable spice trade.

David Reubeni envisions a grand alliance between three Christian kings and one Jewish kingdom: King Charles V of the Holy Roman Empire, the King of France, Prester John – the western alias given to the Emperor of Ethiopia, and the Jewish kingdom of Khaibar governed by Reubeni's brother.

The broader aim of this alliance is meant to provide the necessary force of men in arms to expel the Ottoman Turks from the Land of Israel, and to facilitate what Reubeni believes is the imminent redemption of the oppressed nation of Israel.

To achieve this objective, Reubeni needs to enlist the help of Pope Clement VII, and, therefore, he had set out for Rome.

In Rome, with the help of a Jewish friend, he lays out his detailed plans before the Pope, who says to him that he cannot personally get involved in helping to build such a coalition, but nevertheless refers David Reubeni to John III, the king of Portugal, who is directly related to King Charles by virtue of his marriage with his sister.

Acquiescing, David Reubeni then sets sail from Italy for Portugal, accompanied with a brief and letters of recommendation from the Pope to help facilitate his errand.