The Birth of Venus to Botticelli's Florentine contemporary, and Lorenzo di Medici's court poet, Angelo Poliziano. The iconography of "The Birth of Venus" is similar to a description of a relief of the event in Poliziano's poem the "Stanze per la giostra", commemorating a Medici joust in 1475, which may also have influenced Botticelli, although there are many differences. For example Poliziano talks of multiple Horae and zephyrs. Older writers, following Horne, posited that "his patron Lorenzo di Pierfrancesco asked him to paint a subject illustrating the lines", and that remains a possibility, though one difficult to maintain so confidently today. Another poem by
Sandro Botticelli Pollaiuolo and others, although views on this differ. A Botticello who was probably Sandro's brother Giovanni was close to Lorenzo. Although the patrons of many works not for churches remain unclear, Botticelli seems to have been used more by Lorenzo il Magnifico's two young cousins, his younger brother Giuliano, and other families allied to the Medici. Tommaso Soderini, a close ally of Lorenzo, obtained the commission for the figure of "Fortitude" of 1470 which is Botticelli's earliest securely dated painting, completing a series of the "Seven Virtues" left unfinished by Piero Pollaiuolo. Possibly they had been introduced by a Vespucci