The Hermès Birkin prototype, originally made for Jane Birkin, sold at a Sotheby's auction in Paris for $10.1 million. What to know about the unique and coveted purse.

The original bag custom-made for actress Jane Birkin, which became one of the era-defining designs of the 20th century, was sold in Paris on Thursday for a record 8.6 million euros ($10.04 million), auctioneer Sotheby's said.