Martti Ahtisaari, who has died aged 86, was a former president of Finland who won the Nobel peace prize for his role as an independent mediator helping to end conflicts in Namibia, Kosovo, Northern Ireland and Indonesia.

His efforts were particularly useful in 1999 in the crisis over Kosovo after a two-month bombing campaign by Nato had failed to get Serbia’s hardline president Slobodan Milošević to withdraw his troops and police from the disputed province and end the ethnic cleansing of Kosovo’s Albanian majority.