Salah Abdeslam - a Belgian born French national of Moroccan origin - was arrested in 2016 following an extended manhunt after the Paris attacks.
He will appear before the Brussels court today on charges of terrorism, attempted murder and possession of firearms.
The Belgian charges relate a gunfight with police at the moment of his arrest in the Brussels suburb of Molenbeek
He could face up to 40 years in jail if convicted.
The four-day trial is being closely observed from France where he will face charges relating to the Paris attacks in 2015 in which 130 people were killed
He is the last survivor of the cell which carried out those attacks. Attacks claimed by the Islamic State group
It is also hoped he has information on the Brussels airport and metro attacks which claimed the lives of 32 poeple, four days after his arrest.
During his two years in custody Abdeslam has remained silent, refusing to answer questions from French and Belgian prosecutors.
He has insisted however on attending the Brussels trial, which has raised hopes that he might for the first time break his silence and shed light on attacks.