Boxing icon Muhummad Ali has passed away at the age of 74.

Ali, formerly known as Cassius Clay, had been in ailing health for quite some time and was brought to hospital in Phoenix, Arizona on Thursday as a precautionary measure. However, within a day, doctors informed Ali's close family to expect the worst.

Ali was diagnosed with Parkinson's at the age of 42 and had become increasingly frail in recent years as his condition deteriorated. However, in his prime, Ali was considered the greatest boxer of a generation.

Already, tributes have poured in from all corners of society with Bill Clinton, former rival George Foreman, Manny Pacquiao, Oscar De La Hoya and many more offering up condolences and support to Ali's extended family.

Here's a short trailer from the excellent RTE documentary, When Ali Came To Ireland, which charted his 1972 visit to this country.