Judges at the world`s only permanent war crimes court will on Tuesday pass sentence on former Congolese leader Jean-Pierre Bemba, with prosecutors calling for a minimum 25-year sentence.
If the judges agree with the prosecution, it will be the highest jail term ever imposed by the International Criminal Court in a case that was the first there to focus on rape as a weapon of war.
Prosecutors blamed the former vice president of the Democratic Republic of Congo for turning a blind eye to a reign of terror by his troops in the Central African Republic from October 2002 to May 2003.
He was found guilty in March of five charges of war crimes and crimes against humanity, after sending some 1,500 troops from his private army into CAR to help quash a coup against the then president.
Bemba`s Congolese Liberation Movement (MLC) carried out a series of rapes and murders as they sought to prop up then president Ange-Felix Patasse.
Experts testified that the brutality of the events would have long-term traumatic effects on the victims and their communities.
In their verdict handed down at the end of a trial which began in November 2010, the ICC judges found that despite knowing what was happening, Bemba "failed to take all necessary and reasonable measures to prevent" a litany of crimes, which included the gang rapes of men, women and children, sometimes as their relatives were forced to watch.
Bemba, 53, will become the highest level person sentenced at the tribunal based in The Hague.
The prosecution`s request for a 25-year sentence "does reflect the gravity of these crimes," human rights activist Carrie Comer told AFP.
The ICC has previously sentenced two others convicted there to 14 and 12 years in prison.As well as the issue of rape as a weapon of war, the Bemba case was also the first at the ICC to focus on a military commander`s responsibility for abuses by his troops, even if he did not order them.
Defence lawyers have argued that Bemba, who has already spent eight years in detention since his 2008 arrest in Brussels, should be released.
Bemba "did not participate in the crimes. He was not standing there and encouraging his troops... Mr Bemba was not even in the same country," defence lawyer Peter Haynes said at an ICC hearing last month.
His "culpability arises from his failure to control a small fraction of his troops who were thousands of miles away".
Activists warn however that a light sentence would fail to send a warning to other military commanders.
"It`s really important that the court recognise the command responsibility .. and there`s an opportunity here to provide a deterrent," said Comer, the permanent representative to the ICC for the International Federation for Human Rights (FIDH).
"If you knew, or you should have known, that these things were going on and you execute effective control over your troops then, yes, you`re absolutely responsible for ... not preventing or punishing these crimes."
The FIDH, which represents some 178 rights organisations from the around the world, is also hoping "the trial chamber will come back with a strong sentence on this in recognition of the particular devastating harm that sexual and gender-based crimes have on victims, their families and their communities at large."
The landmark Bemba verdict was hailed at the time, even though many were shocked at how long it had taken for sexual violence to be focused on in an international trial.
American actress Angelina Jolie urged the international community "to build on the important legal precedent" set by the Bemba case so that "we can collectively shatter impunity for the use of rape as a weapon of war and terrorism".