Some scholars associate Yehudah Cresques/Jacobus Ribus with one Mestre Jacome de Malhorca who is purported to have worked as a royal mapmaker in Portugal in the 1420s in the court of Prince Henry the Navigator (Infante Dom Henrique o Navegador), although this is debated. What is clear is that we see a number of Converso mapmakers with origins in Majorca working in 15th-century Iberia, of whom Mestre Jacome is one. A Haim Ibn Risch is attested, possibly Yehudah’s son, converted under the name Juan de Vallsecha. Haim/Juan’s son, Gabriel de Vallsecha (Vallseca, Devallsecha), is also known as a mapmaker. In 1439, de Vallsecha made a portolan map that was acquired by
Amerigo Vespucci (it’s currently owned by the
Museu Marítim de Barcelona; you can see a similar one he made, from 1447,
at the BNF, here and pictured above, and a third version dates from 1449.) Meciá de Viladestes, almost certainly a Converso, produced a
portolan map in 1413. One Yehudah Ibn Zara (Abenzara) was working in the later 15th century;
Cecil Roth wrote a
pamphlet about him.
Jews and Conversos were not the only mapmakers in the Mediterranean during the period, during which many portolan maps were produced; but they are noticeably represented, especially in the Balearics. At the same time, they belong to a small phenomenon. We don’t know for sure, but it’s likely that many of the Majorcan Jewish cartographers were either from a single family, or acquired the skills required for mapmaking as students (or students of students) of that family. This small but distinguished group marshalled knowledge valued in Sefardi Jewish culture, even after being forcibly converted, to create an enduring picture of the world.