By Crispin Thorold
BBC News, Jerusalem
Former Israeli Prime Minister, Ariel Sharon, who is still in a coma two years after suffering a massive stroke, has reached the age of 80.
Doctors are not optimistic that Mr Sharon will recover
Mr Sharon's close friends and family marked his birthday on Tuesday with a private visit to his hospital bed.
Ariel Sharon's closest adviser told the BBC that this was a day marked with tremendous sadness.
In the coming days, one of Mr Sharon's sons will begin a nine-month jail sentence for illegal fundraising.
Omri Sharon - a former member of the Knesset, the Israeli parliament - was convicted of illegal fundraising for his father.
Mr Sharon's two sons are thought to have gone to the hospital for the birthday.
Dov Weisglass, who spent decades advising Ariel Sharon, also visited him at the Sheba Medical Center in central Israel.
"This is a day marked with tremendous sadness," Mr Weisglass said.
"My hopes and prayers are that he will recover but as time goes by the chances of that happening decline. The doctors taking care of him are not optimistic.
"It is very difficult to talk about the legacy of someone who was part of the process of making history."