The BBC's Mark Doyle looks at which former African leaders are in the running to win the $5m leadership prize.
Mozambique's Mr Chissano has strong credentials as a democrat
The Mo Ibrahim Foundation is next month due to award over $5m to the former African head of state adjudged to have demonstrated exemplary leadership.
The presidential prize is aimed at encouraging best practice.
The lucky recipient of what the organisers call "the world's biggest prize" will be named on 22 October.
The winner will then be paid the $5m in tranches over a period of 10 years, with a further $200,000 for life thereafter.
The international panel of judges includes former UN Secretary General Kofi Annan, former Irish President Mary Robinson and the respected ex-Finance Minister of Nigeria, Ngozi Okonjo-Iweala.
All 13 African heads of state or government who left office between 2004 and 2006 are eligible for the cash prize - including, perhaps surprisingly, the former transitional president of war-torn Somalia.
Others in the running include the former presidents of:
- Benin - Mathieu Kerekou
- Mozambique - Joaquim Chissano
- Tanzania - Benjamin Mkapa
These candidates could advance a claim to have behaved well.
Mr Kerekou, for example, was the first mainland African head of state to have allowed free multiparty elections - and to have then stood down when he lost.
Mr Chissano played a key role in ending the war in Mozambique.
Mr Mkapa kept Tanzania on a relatively stable political course despite unrest in neighbouring countries.
Curiously, the late military strongman of Togo, Gnassingbe Eyadema, who died in office, is also on the list of possible recipients.
The prize might persuade Bakili Muluzi to relinquish further ambitions
A spokesman for the Mo Ibrahim Foundation stressed that the list was a "long list" of all the former heads of state or government and not a "shortlist" chosen by the prize committee.
One of the men named in the "long list", former President Bakili Muluzi of Malawi, told me through a trusted contact that he did not think he qualified for the prize because he does not want to be an "ex-president".
Mr Muluzi intends to stand for office again - and is currently engaged in a controversial political and legal battle to do so.
A senior diplomat posted to Malawi told me Mr Maluzi's new bid for power had caused "political deadlock".
He speculated that the prize raises the fascinating possibility that it could end that deadlock by tempting Mr Muluzi into retirement with a handsome pension.