The military wing of Hamas, the Izz al-Din al-Qassam Brigades, announced on Thursday the death of its longtime chief of staff, Mohammed Deif, a man who eluded Israeli capture for decades and was said to move like a ghost, thus earning the moniker "The Guest" or "Deif" in Arabic.

Israel declared it had killed the 59-year-old Deif in an air strike in al-Mawasi in southern Gaza in July, but there had been no confirmation from Hamas. 

Deif, whose real name is Mohammed Diab Ibrahim al-Masri, is believed by many to have been one of the planners of the 7 October 2023 Hamas-led attacks on southern Israel.

Just hours after the dawn raid into Israel that day, Deif delivered a rare audio message proclaiming the start of the operation called "The al-Aqsa Flood" and called on Palestinians in Israel to "expel the occupiers and demolish the walls”. 

While little is known about his life, Deif had a wife and two young children until 2014, when all of them were killed in an Israeli air strike. 

He had been sought by Israel since the early 1990s after he carried out attacks on Israeli soldiers.

In 2002, he assumed the title of chief of staff for the Qassam Brigades and is believed to have been the creator of the "Shadow Unit" that guards and hides Israeli captives. Members of that unit, dressed in black, have been seen escorting released Israeli captives for their handover to the International Committee of the Red Cross this month. 

In December 2023, the Israeli army air-dropped fliers across Gaza offering $100,000 to anyone with information on Deif’s whereabouts, adding that “confidentiality is assured” for Palestinians who come forward.  

Despite eluding capture, Deif sustained life-altering wounds from repeated attempts to assassinate him, which impacted his mobility and vision, Israeli reports have said. Hamas never confirmed those details. 

In a statement shared on Telegram by the Qassam Brigades, Deif was described as a “great leader” who was a “living example of courage”.

“We bid farewell to the leader Abu Khaled,” the Brigades said, using his colloquial name among Palestinians.