Joan of Arc was captured by the Burgundians at the siege of Compiègne on 23 May 1430. The Burgundians transferred her to the English, who organised a trial headed by Pierre Cauchon, Bishop of Beauvais and member of the English Council at Rouen. Joan was convicted and burned at the stake on 30 May 1431. After the death of Joan of Arc, the fortunes of war turned dramatically against the English. Most of Henry's royal advisers were against making peace. Among the factions, the Duke of Bedford wanted to defend Normandy, the Duke of Gloucester was committed to just Calais, whereas Cardinal Beaufort was inclined to peace. Negotiations stalled. It seems that at the congress of Arras, in the summer of 1435, where the duke of Beaufort was mediator, the English were unrealistic in their demands. A few days after the congress ended in September, Philip III, duke of Burgundy, deserted to Charles VII, signing the Treaty of Arras that returned Paris to the King of France. This was a major blow to English sovereignty in France. The Duke of Bedford died on 14 September 1435 and was later replaced by Richard Plantagenet, 3rd Duke of York.
Question: How many months passed in 1435 when the Duke of Bedford died?
Answer: 9