That I might take part in everything, and bear me like the rest, I did tilt in the Piazza of Santa Croce—which tilting occasioned an outlay of ten thousand florins—and although I was very vigorous neither of my years nor of blows, yet was the first prize awarded unto me, namely, a helmet adorned with silver and having a figure of Mars for the crest.
Per eseguire e fare come gli altri, giostrai in sulla piazza di Santa Croce con grande spesa, e grande sunto; nella quale trovo si spese circa fiorini 10 mila di sugello; e ben che d’armi e di colpi non fussi molto strenuo, mi fu giudicato il primo onore, cioè un elmetto fornito d’ariento, con un Marte per cimiero.
Original text (Italian)
Source, in full
On the jousting tournament held in the Piazza Santa Croce on 7 February 1468, in Lorenzo's Ricordi (c. 1483–5), reported in Isidoro Del Lungo, Women of Florence, tr. Mary C. Steegmann (London: Chatto and Windus, 1907) p. 190