Mozart's handwritten music sheet and a military letter from King Henry VIII are among the items being auctioned in the United Kingdom's well-known auction house Christie's under the "Valuable Books and Manuscripts" sale.

Written in July 1513 – a month before the English victory at the Battle of the Spurs, Henry's letter to his lieutenant-general in France calls on him to capture the town of Therouanne and recruit German mercenaries fighting for the French to come to fight for the English.

The letter has an estimate of 25,000 pounds to 35,000 pounds ($30,702 to $42,983).

"Whereas we do occasionally see Henry VIII letters coming up, what’s particularly rare about this one is that it’s a campaign letter, it’s about war, it’s about his strategy," Mark Wiltshire, a specialist in the books and manuscripts department at Christie's London, told Reuters.

"It’s about him as a Machiavellian figure trying to work out exactly the best way of defeating his opposition."

Also on offer at the Dec. 14 auction is an autograph music manuscript written by Mozart in 1773 when he was living in Salzburg to celebrate a family friend's graduation from university.

The sheet of music, which features the opening 15 bars of the second movement of the Serenade in D major for orchestra, is the highlight among a collection of music lots, including autograph letters by composers Felix Mendelssohn, Hector Berlioz and Johannes Brahms.

It has an estimate of between 80,000 pounds to 120,000 pounds.

"There’s always great excitement when anything like this from Mozart comes up," Wiltshire said.