An Ankara court is set to begin hearing the case against 94-year-old former general and president Kenan Evren.
Along with Turkey's former air force commander, he is to face trial over a 1980 military coup.
During the three-years of military rule, 50 people were executed and half a million were arrested.
Hundreds died in Turkish jails, and many more disappeared.
One survivor remembers the violence over a quarter century ago.
(SOUNDBITE) (Turkish) TURKISH COUP VICTIM ELMAS DUMAN SAYING:
"Our houses were stormed. We were taken into custody without any particular reason. We were subjected to torture. We came here today to be co-plaintiffs. We are writing our
petitions and we want all of them to be tried. "
At least 350 individuals and groups have applied to be co-plaintiffs in the trial, meaning their grievances will be taken into account during the prosecution and possible sentencing
phases.
On Tuesday, Prime Minister Erdogan's government also joined groups applying to be co-plaintiffs.
Evren is now frail and is unlikely to appear in court, having recently undergone intestinal surgery, and Turkish media report that he also has a broken arm.
But the prosecutor's office said both defendants may give testimony via video link.
Travis Brecher, Reuters
