1. Codex Leicester Leonardo da Vinci ($49.4 mil 1, 1994)
Bill Gates bought this handwritten notebook of scientific musings.
2. The Gospels of Henry the Lion Order of St. Benedict ($28 mil, 1983)
The German government owns this 12th-century work commissioned by the Duke of Saxony.
3. Magna Carta ($24.5 mil, 2007)
One of just 17 surviving 12th-century versions passed from one American billionaire (Ross Perot) to another (Carlyle Group cofounder David Rubenstein).
4. St. Cuthbert Gospel ($15.1 mil, 2011)
The Jesuits sold this 7th-century work–interred alongside St. Cuthbert in 698 and unearthed in 1104–to the British Library.
5. Bay Psalm Book ($14.5 mil, 2013)
Rubenstein bought one of 11 surviving copies of this 1640 book.
6. The Rothschild Prayerbook($13.9 mil, 2014)
Medieval devotional book of hours originally part of a collection confiscated by the Nazis in 1938.
7. Birds of America John James Audubon ($12.6 mil, 2010)
Hundreds of drawings produced in the 1820s; sold to London art dealer Michael Tollemache.
8. The Canterbury Tales Geoffrey Chaucer ($11.1 mil, 1998)
Produced by William Caxton, reputedly England’s first printer.
9. Copy of the Constitution, Bill of Rights and other key acts of the first Congress in 1789 George Washington ($10.2 mil, 2012)
Sold to the Mount Vernon Ladies Association, a nonprofit that owns Washington’s Virginia estate.
10. Comedies, Histories, & Tragedies (1623), The First Folio William Shakespeare ($8.2 mil, 2001)