46 autographed letters from the French poet Guillaume Apollinaire sold with a 10.7% increase on estimate at Sotheby's Paris showroom yesterday (May 15).

Apollinaire's letters to André Level

The letters, which span the entirety of the poet's military career during the first world war, were sent to André Level, Apollinaire's mentor and patron. The war saw a turning point for the writer and spawned his most noted work, Calligrammes, a collection of modernist and concrete poetry relating to his experiences.

The letters sold for €276,750, against an estimate of €150,000-250,000, and featured as the star lot in Paris.

Apollinaire's Case D' Armons, a collection of poems in honour of those he served alongside during the war, brought €108,750. The work was specially collated and printed to order for Apollinaire's friends, and is one of just 20 extant examples.

One of the auction's most impressive sales came from Henry de Boulainvilliers' 1731 work, Histoire des Arabes avec la Vie de Mahomet. Describing the history of the Arabian world and the life of the prophet Muhammad, the work was a major source of inspiration for Voltaire's tragedy, Mahomet.

The fantastic edition brought €132,750, smashing its estimate of €18,000-25,000 and achieving an increase of 430.9%.

A collection of 91 coloured sketches and notes by Orson Welles for his film adaptation of Franz Kafka's The Trial brought another of the auction's highlights. The collection comprised Welles' initial thoughts and ideas for the backdrops to scenes involving the film's protagonist, K.

Achieving a final price of €89,950 against an estimate of €30,000-50,000, the piece saw a 79.9% increase.

The Academy Award which Orson Welles received for Citizen Kane made $861,542 at auction in December 2011.

A brilliant selection of rare manuscripts is currently on offer over at PFC Auctions. This personal collection of letters from Winston Churchill regarding his dog, Rufus II, provides a superb insight into the personality of the war-time leader.