Jan. 31, 2005 : The Vatican announces the pope has a mild case of flu.

Feb. 1: The pope is rushed to hospital with breathing difficulties.

Feb. 10: He is discharged from hospital.

Feb. 24: He undergoes a successful operation to insert a tube in his throat to relieve breathing problems.

March 13: He is discharged from hospital.

March 20: The pope is physically unable to lead the traditional Holy Week services that start with Palm Sunday.

March 27: The pope appears before thousands of Easter pilgrims. He struggles to speak but ultimately fails.

March 30: The breathing tube makes it difficult for the pope to eat, so a feeding tube is inserted through his nose so he can receive adequate nutrition.

March 31: High fever from a urinary tract infection causes brief heart failure. Officials describe his condition as `very grave.`