Duckenfield was the match-day commander at the FA Cup semi-final between Liverpool and Nottingham Forest at Sheffield Wednesday's Hillsborough ground on 15 April, 1989.
Duckenfield, 74, has pleaded not guilty to 95 counts of gross negligence manslaughter following the fatal crush in the Leppings Lane end.
There is no manslaughter charge over the death of a 96th casualty, Anthony Bland, as he died almost four years later, and under the law in 1989 his death is considered "out of time" to be prosecuted.
Duckenfield sat next to co-defendant, former Sheffield Wednesday club secretary Graham Mackrell, who is charged with an offence involving the stadium safety certificate and a health and safety offence.
Hillsborough is Britain's worst sports stadium disaster. Families of the victims fought a long campaign for events surrounding the tragedy to be re-investigated. They gained their breakthrough when the Crown Prosecution Service announced it would press charges in June 2017.
Around a dozen family members were at Preston crown court in north-west England for the start of proceedings.
Former police officers Donald Denton and Alan Foster, plus retired lawyer Peter Metcalf, will go on trial in September, charged with doing acts intended to pervert the course of justice.