The trial is expected to last seven months, with the verdict delivered by the jury after hearing about 370 people.
Ten men are going on trial in Belgium on the charge of playing a role in two suicide bombings that caused the death of 32 people and injured more than 300 in Brussels in 2016.
The ISIL (ISIS) armed group claimed responsibility for the attacks, which also saw three of the alleged perpetrators from the group – Khalid el-Bakraoui, Ibrahim el-Bakraoui and Najim Laachraoui – die.
On Monday, presiding judge Laurence Massart will confirm the identity of all parties to the case, including the defendants and lawyers representing about 1,000 people affected by the attacks.
She will then address the jury, selected from a pool of 1,000 Belgians last week in a process lasting 14 hours.
The event will take place at the Court of Assizes – the one which deals with the country’s biggest criminal cases and was also NATO’s former headquarters in Belgium.
Link to Paris attacks
The Brussels bombings trial has clear links to the French trial over the November 2015 Paris attacks.
Six of the Brussels bombings accused were sentenced to jail terms of between 10 years and life in France in June, but the Belgian trial will be different in that it will be settled by a jury, not judges.
The twin bombings at Brussels Airport and a third bomb on the city’s metro on March 22, 2016 killed 15 men and 17 women – Belgians, Americans, Dutch, Swedish, British, Chinese, French, German, Indian, Peruvian and Polish, many based in Brussels, the home to EU institutions and military alliance NATO.
Nine men are charged with multiple murders and attempted murders in a “terrorist” context, with potential life sentences, and all 10 with participating in the activities of a “terrorist group”.
They include Mohamed Abrini, who prosecutors say went to the airport with two suicide bombers but fled without detonating his suitcase of explosives, and Osama Krayem, a Swedish national accused of planning to be a second bomber on the Brussels metro.
Salah Abdeslam, the main suspect in the Paris trial, is also an accused, along with others prosecutors say hosted or helped certain attackers.
One of the 10, presumed killed in Syria, will be tried in absentia.
In accordance with Belgium court procedure, the defendants have not declared whether they are innocent or guilty.
Prosecutors are expected to start reading from the 486-page indictment on Tuesday before hearings of about 370 experts and witnesses can begin.
The trial is expected to last seven months and is estimated to cost at least 35 million euros ($36.9m).