Task: Question Generation
Input (English): Passage: Following this victory, Edward realized that to create a force capable of retaking Jerusalem it would be necessary to end the internal unrest within the Christian state, and so he mediated between Hugh and his unenthusiastic knights from the Ibelin family of Cyprus.  In parallel to the mediation, Prince Edward and King Hugh began negotiating a truce with Sultan Baibars; a 10-year-10-month-and-10-day agreement was reached in May 1272, at Caesarea. Almost immediately Prince Edmund departed for England, while Edward remained to see if the treaty would hold. The following month, an attempt to assassinate Edward was made. Several versions of who sent the assassin exist. According to different versions, the assassin was sent by the emir of Ramlah or by Baibars. Some legends also say that the assassin was sent by the "Old Man of the Mountains", leader of a heretical Muslim sect. Edward killed the assassin but received a festering wound from a poisoned dagger in the process, further delaying Edward's own departure. In September 1272, Edward departed Acre for Sicily and, while recuperating on the island, he first received news of the death of his son John, and then a few months later news of the death of his father.  In 1273 Edward started his homeward journey via Italy, Gascony and Paris. Edward finally reached England in the middle of 1274, and was crowned King of England on 19 August 1274.
Output (English): After Edmund left, how much time passed before the assassination attempt on Edward was made?