Short answers, pulled from the story.
Michelangelo created the square tempera work on canvas in August 1530 after returning to Florence. The composition was complete by mid-October 1530 before he refused delivery to Duke Alfonso I d'Este.
Queen Anne of Austria ordered the destruction of the original canvas during the seventeenth century due to perceived lasciviousness. An inventory document from 1691 records this act of erasure by royal command alongside a drawing marked for burning.
The best known copy resides today in London's National Gallery where it was once attributed to Rosso Fiorentino. Other versions exist in Dresden's Gemäldegalerie, Berlin's Gemäldegalerie, and Venice's Correr Museum.
The painting depicted Jupiter transformed into a swan making love to a reclining Leda along with an egg and twin children Castor and Pollux born from that union. This composition drew directly from ancient Roman gems and seals found in archaeological collections.
Michelangelo returned to Florence in August 1530 after inspecting city walls as governor general of fortifications. He used his time in hiding to create the work but refused delivery to the Duke after Alfonso called it a little thing within Michelangelo's hearing.