Stella deâ Tolomei (died 1419) was an Italian noblewoman and the official mistress of Niccolò III d'Este, Marquis of Ferrara. Although never married to Niccolò, she held a prominent position at the Este court and bore him several children, including Leonello d'Este, who later became Marquis of Ferrara, and Borso d'Este, the first Duke of Ferrara. Her relationship with Niccolò granted her significant status and influence during her lifetime.
Stella deâ Tolomei had several children with Niccolò III dâÂÂEste, many of whom were acknowledged and later legitimized:
All three sons played significant roles in the Este dynasty, and both Leonello and Borso ascended to rulership despite their illegitimate birth.