Write a question about the following article: A large number of minor nobles also joined the Crusade and before long, according to Arnold von Lübeck in his Arnoldi Chronica Slavorum, a powerful military host of 60,000, including 7,000 German knights, was on its way. A contemporary chronicler gave a lower estimate of 4,000 knights and an unknown amount of infantry. German historian Claudia Naumann suggested in 1994 that the Crusade had 16,000 men, including 3,000 knights.Bretislaus III, Duke of Bohemia had agreed to join the Crusade at the Diet in Worms on December 1195, and planned to do so, until he fell ill and died on 15 or 19 June 1197. In March 1197 Henry proceeded to the Kingdom of Sicily. The crusaders embarked for Acre, while the emperor first had to suppress an armed revolt in Catania. A force of 3,000 Saxon and Rhenish troops in 44 ships under Count Palatine Henry V and Archbishop Hartwig of Bremen sailed from northern Germany and arrived in Messina in August, where they merged with the emperor's troops and sailed to the Eastern Mediterranean. Still in Sicily, out for hunting near Fiumedinisi in August, Emperor Henry fell ill with chills, possibly from malaria. He died on September 28 before he could set sail for the Holy Land.

Question about the article:
How many months after the Duke of Bohemia agreed to join the Crusade at the Diet in Worms did he die?