The International Criminal Court (ICC) has ruled that four senior Kenyan officials are to stand trial over violence after the 2007 election.
Those who will stand stand trial are Finance Minister Uhuru Kenyatta and cabinet secretary Francis Mutaura.
They are accused of crimes against humanity, including murder and persecution.
In a separate case, ex-minister William Ruto and radio presenter Joshua arap Sang will also stand trial.
All have denied the allegations against them.
Charges against two others were not confirmed.
More than 1,200 people were killed in weeks of unrest after the 2007 poll.
Some 600,000 people were forced to flee their homes.
The violence began as clashes between supporters of the two rival presidential candidates - Raila Odinga and Mwai Kibaki - but it snowballed into a bloody round of score-settling and communal violence.
Chief prosecutor Luis Moreno-Ocampo has asked to bring two separate cases, reflecting the ethnic divisions behind Kenya's post-election violence.
Mr Kenyatta, a supporter of Mr Kibaki, is accused of organising a campaign of violence including murder and rape against Odinga supporters.
Prosecutors say he met members of a secretive criminal organisation known as Mungiki at a shopping centre in Nairobi before the election in 2007 to arrange some of the attacks.
He denied the accusation at a preliminary hearing at The Hague-based court last September.
Mr Kenyatta, the son of the country's first President Jomo Kenyatta, is hoping to stand in next year's presidential poll, with analysts suggesting that he has a realistic chance of winning.
Two other senior Kibaki supporters face similar allegations.
Mr Ruto, a former education minister, says he also intends to run in the election.
He and two other supporters of Mr Odinga in the 2007 poll face claims that they organised attacks on Kibaki supporters.
Monday is a big day for Kenya, as the people are eagerly awaiting the court's decision, the BBC's Will Ross in Nairobi reports.
Kenya's government has been lobbying for the cases to be dropped - a position endorsed last year by the African Union.
Mr Kibaki was eventually declared the winner of the 2007 election, and is serving his second term as president. Mr Odinga was installed as prime minister under a power-sharing deal brokered by Kofi Annan to end the violence.
Mr Ruto and Mr Odinga have since fallen out and are expected to face each in the elections.