Daniel de Fonseca (1672 - c. 1740) was a distinguished Portuguese Marrano Jew who served as court physician and advisor to several notable European rulers.
[2] It was also during this time that de Fonseca exemplified himself as an excellent physician, quickly being employed by several notable Ottoman aristocrats.
After the Battle of Poltava, de Fonseca aided King Charles XII of Sweden in his intrigues which he sustained during the Great Northern War.
He held this office until 1719, when in March of that year, he moved to Bucharest to serve as a physician and advisor to Prince Nicholas Mavrocordato of Wallachia.
It was this relationship with Prince Nicholas, that allowed de Fonseca to secure the relative civil liberties of local Jewish communities.