There are many ways to rank greatness but Olympic gold medals and world long-course records must make any list. Here is how Thorpe figures

NUMBER OF INDIVIDUAL WORLD RECORDS

26: Mark Spitz (USA, 1967-72)

18: Roland Matthes (GDR, 1967-73)
15: Ragnhild Hveger (DEN, 1937-41); Dawn Fraser (AUS, 1956-64); Donna de Varona (USA, 1960-64); Debbie Meyer (USA, 1967-70); Michael Phelps (USA, 2001-06)
13 Ian Thorpe (AUS, 1999-2002)

NUMBER OF INDIVIDUAL OLYMPIC GOLD MEDALS

5: Krisztina Egerszegi (HUN, 1988,92,96)

4: Mark Spitz (USA, 1972); Roland Matthes (GDR, 1968-72); Tamas Darnyi (HUN, 1988-92); Janet Evans (USA, 1988-92); Alexander Popov (RUS, 1992-96); Inge de Bruijn (NED, 2000-04) Michael Phelps (USA, 2004)
3 Johnny Weissmuller (USA, 1924-28); Murray Rose (AUS, 1956-60); Dawn Fraser (AUS, 1956,60,64); Mike Burton (USA, 1968-72); Vladimir Salnikov (USSR, 1980, 88); Michael Gross (GER, 1984-88); Brooke Bennett (USA, 1996-00); Ian Thorpe (AUS, 2000-04); Pieter Van Den Hoogenband (NED, 2000-04)

NB: some swimmers have been excluded where it was subsequently proven that performance-enhancing drugs played a part in their career.

There can, of course, be no question that Thorpe is the greatest middle-distance freestyler of his generation. He leaves the sport sporting the fastest nine times ever recorded over 400m freestyle, Grant Hackett coming in at number 10, and holds nine of the top ten fastest 200m times ever, broken by Pieter Van Den Hoogenband at number six.

And here at a glance is Thorpe's record compared to a couple of those who set the pace before him in similar territory:

Murray Rose (AUS)

WR: 400m - 3; 800m - 1; 1,500m - 2
Longevity: held strong when it counted; first man to retain the 400m Olympic title; too the eight-lap world record from 4:27 to 4:13 over five years; robbed of a place at the 1964 Games because he inadvertently missed trials in February, he made his point by setting his final world record, over 1,500m freestyle in August 1964 but officials denied him a place in Tokyo
Olympic Games:
400m freestyle: Gold 1956; Gold 1960
1,500m freestyle: Gold 1956; Silver 1960
There were no World Championships in Rose's day but he shared top billing over a six-year period with fellow Australian John Konrads

John Konrads (AUS)

WR: 200m - 3; 400m - 4; 800m - 3; 1,500m - 2
Longevity: held strong when it counted; first man to retain the 400m Olympic title; too the eight-lap world record from 4:27 to 4:13 over five years
Olympic Games:
400m freestyle: Bronze 1960
1,500m freestyle: Gold 1960;
There were no World Championships in Konrad's day but he shared top billing over a six-year period with fellow Australian Murray Rose

Don Schollander (USA)

WR: 200m - 9; 400m - 3
Longevity: held the 200m record from 1963 to 1969 with just one break of two months, when German Hans-Joachim Klein intervened
Olympic Games:
200m freestyle: none held in 1964; Silver 1968
400m freestyle: Gold 1964 (wr)
There were no World Championships in Schollander's day but he held the fastest time in the world in every year from 1963 to 1968 over 200m and the fastest time in the world from 1963-66 over 400m.

Vladimir Salnikov (USSR)

WR: 400m - 6; 800m - 4; 1,500m - 3
Longevity: held the 1,500m record from 1980 to 1991 and came back eight years after winning his first Olympic crown over 30 laps to winning his second
Olympic Games:
400m freestyle: Gold 1980;
1,500m freestyle: Gold 1980 (wr); Gold 1988
World (l/c) Championships:
400m freestyle: Gold 1978; Gold 1982
800m freestyle: not held in his era
1,500m freestyle: Gold 1978; Gold 1982

Michael Gross (FRG)

WR: 200m - 4; 400m - 1 (also butterfly 100m - 1; 200m - 4)
Longevity: held the 200m butterfly record for six years, the 200m freestyle record for five years, the 400m record for almost three years; first man to retain world titles at 200m freestyle and 200m butterfly and only man to win both titles twice
Olympic Games:
200m freestyle: Gold 1984 (wr)
100m butterfly: Gold 1984 (wr)
200m butterfly: Silver 1984; Gold 1988
World (l/c) Championships:
200m freestyle: Gold 1982; Gold 1986;
100m butterfly: Silver 1982; Silver 1991
200m butterfly: Gold 1982; Gold 1986; Silver 1991

Ian Thorpe (AUS)

WR: 200m - ; 400m - 5; 800m - 1
Longevity: Unbeaten from 1998 to retirement in 2006 over 400m long-course; no-one has come close to Thorpe's world records over 200m and 400m, which may be on the books for some time yet.
Olympic Games:
200m freestyle: Silver 2000; Gold 2004
400m freestyle: Gold 2000 (wr); Gold 2004
World (l/c) Championships:
200m freestyle: Gold 2001 (wr); Gold 2003
400m freestyle: Gold 1998; Gold 2001 (wr); Gold 2003
800m freestyle: Gold 2001 (wr)