Who was the Lady in this Portrait Oil Painting

There are known only three female portraits of which Krakow's Lady with an Ermine is arguably the most beautiful. It's also in the best shape after the 500-plus years that elapsed. Leonardo's masterpiece in The Czartoryskich Museum at 19 Sw. Jana street depicts a delightful teenage beauty, most probably Cecilia Gallerani who was the mistress of Milan's ruler Lodovico Sforza il Moro, the artist's patron. Most likely Leonardo da Vinci painted her in his early thirties, between 1482 and 1485 – i.e. some 20 years before the Paris Louvre's famed Mona Lisa – and for the first time he showed the sitter in the way that would soon become the standard. Art historians maintain it's the world's first modern-age portrait ever painted.

At the turn of the 20th century Polish art historians first suggested the "Lady" may be the missing portrait of Cecilia Gallerani. Bellincioni's poem, composed soon after the portrait was completed, and extant correspondence between Gallerani and Isabella d'Este helped scholars identify the picture as such, however, the sitter's identity continued to be a subject of debate until Gallerani's life dates were firmly established in 1992.