Pope John Paul II has suffered increasing health problems since a near-fatal assassination attempt in May 1981.
As his health fails, the Pope still plans public engagements
Right-wing Turkish fanatic Mehmet Ali Agca shot the pontiff several times as he toured St Peter's Square in the Popemobile.
One bullet went through the Pope's abdomen and another just missed his heart. He survived after major intestinal surgery.
He went through further surgery in August of that year after infection took hold.
In 1992 he had major surgery to remove a colon tumour that was becoming malignant.
In 1993, the Pope dislocated his shoulder in a fall at the Vatican, and again spent some time in hospital.
He broke his thigh bone in another fall in his bath in April 1994, having bone replacement surgery as a result. He still limps and uses a cane.
In 1995, a fever forced him to cancel Christmas Mass, while in 1996 he had his appendix removed after repeated "abdominal pains".
Three years later, a bout of influenza forced him to cancel a number of activities at the Vatican.
The same year - 1999 - he had to have three stitches in his forehead after he slipped and hit his head at the Vatican Embassy in Warsaw, Poland.
He has suffered from Parkinson's Disease for some time, with slurred speech and a trembling left hand the outward symptoms.
The Pope was visibly ill during a visit to France in 1996
He also has arthritis in one of his knees.
He already uses a stick and for the past two years has been using a wheeled platform which is pushed up the main aisle of St Peter's Basilica for services.
On Good Friday 2001, he was for the first time in 23 years as pontiff unable to walk with a cross in the Easter procession in Rome.
And at the following year's Easter celebrations, he was unable to perform the ritual washing and kissing of the feet of priests, a holy ritual symbolising humility.
At the end of September, he cancelled his weekly General Audience in the Vatican because of an intestinal disorder, the Vatican said. However he did appear for the first October General Audience.