Stéphane Breitwieser, born on October 1, 1971, in Mulhouse, France, is perhaps the most prolific art thief you've never heard of—unless, of course, you're a curator who's had the misfortune of encountering his sticky fingers. Between 1995 and 2001, this audacious aficionado "liberated" around 239 artworks from 172 museums across Europe, averaging a heist every 15 days.

Unlike your typical art pilferer seeking profit, Breitwieser fancied himself an art connoisseur with a penchant for 16th and 17th-century masterpieces. His modus operandi? He'd stroll into small, regional museums with his then-girlfriend, Anne-Catherine Kleinklaus, who played the role of lookout. With the finesse of a magician, he'd extract paintings from their frames or pocket small artifacts, all under the oblivious gaze of security.

Breitwieser's first known heist was in early 1994, when he swiped an 18th-century flintlock pistol from the Museum of the Friends of Thann in France. This initial foray ignited a spree that would make even the Pink Panther blush.

His pièce de résistance? Transforming his mother's humble abode into a clandestine gallery, where he and Kleinklaus reveled in their private collection of purloined art. Breitwieser claimed his larceny was driven by love for art, not lucre, stating, "I enjoy art. I love such works of art. I collected them and kept them at home."

However, all good crime sprees must come to an end. In November 2001, after filching a rare 16th-century bugle from the Richard Wagner Museum in Lucerne, Switzerland, Breitwieser was apprehended. A vigilant journalist walking his dog noticed the suspicious character and alerted authorities, leading to Breitwieser's arrest.

The aftermath was nothing short of a Shakespearean tragedy. In a misguided attempt to protect her son, Breitwieser's mother destroyed numerous stolen artworks, discarding them in a canal or incinerating them, resulting in the irreversible loss of cultural treasures.

Stéphane Breitwieser's most valuable theft was "Sybille, Princess of Cleves" by Lucas Cranach the Elder, stolen in 1995 from a castle in Baden-Baden, Germany. In 2003, The Guardian estimated its auction value at over £5 million (approximately €10 million or $10.5 million today).

This painting was among the many artworks Breitwieser stole during his prolific spree across Europe. Tragically, after his arrest, his mother destroyed numerous stolen pieces, including this one, by cutting them up and discarding them, resulting in an irreplaceable loss to cultural heritage.

Breitwieser's escapades have been chronicled in Michael Finkel's 2023 book, "The Art Thief: A True Story of Love, Crime, and a Dangerous Obsession," offering a deep dive into his compulsive collecting and the intricate dynamics with his accomplice girlfriend.

Stéphane Breitwieser faced multiple legal consequences for his extensive art thefts and his mother and ex-girlfriend also received sentences for their involvement. Most recently, in March 2023, a court in Sarreguemines, France, sentenced him to house arrest with an ankle monitor.