MEDICI, COSIMO I DE'. 1519-1574.

MEDICI, COSIMO I DE'. 1519-1574.
Letter Signed ("Fratello et servitor/ Cosimo [contracted] Medici"), a recommendation for Agnolo Niccolini, 1 p, bifolium, 290 x 217 mm, November 6, 1539, the verso with manuscript address and paper seal embossed with the arms of Florence, fold creases, minor browning.
WITH: MEDICI, CARLO DE'. 1595-1666. Autograph Letter Signed, 1 p, folio (264 x 195 mm), n.p. [but probably Rome], July 7, 1631, fold creases, foxing.
Provenance: Frederick P. Delafield (2-page Letter Signed, February 1, 1910, included); Monsignor Fontani (c.1840, according to manuscript note included, referenced in Delafield letter).

Cosimo Medici assumed power in Florence in 1537, and in June 1539 married Isabel of Toledo, consolidating his rule. Agnolo Niccolini (1502-1567) was one of his primary advisors and was instrumental in his rise to power.