Upon the death of his brother Aaron in 1633, the office was given by King Philip IV of Spain to Yahob Caportas (whom Graetz identifies with Jacob Sasportas), a member of an influential Jewish family that rivaled the Cansinos.
Thereupon Jacob Cansino came to Madrid, petitioned the king for the office in consideration of the services rendered by his family to the government, and obtained the appointment in 1636, with a salary of 25 scudi per month.
As a man of letters Jacob Cansino is known for his translation into Castilian of a Hebrew book by Moses Almosnino, under the title Extremas y Grandenzas de Constantinopla, published at Madrid by Francisco Martinez, 1638.
The preface includes an extract from the book of the royal secretary, Augustus Maldonatus, enumerating the various offices held by members of the Cansino family, and a letter from King Philip IV in appreciation of their services.
[3] Jacob Cansino excited the enmity of the Marquis de Los Veles, governor of Oran, who wished to give the office he held to the husband of one of his favorites.