Security is tight at the Supreme Court building in Madrid as 12 Catalan secessionist leaders go on trial for their role in a failed independence bid.
Twelve leaders of Catalonia's separatist movement have gone trial in Spain's highest court on charges relating to an October 2017 independence referendum that was deemed illegal by Madrid.
State prosecutors accuse the defendants of rebellion, disobedience and misappropriation of public funds in relation to the referendum.
Catalans voted overwhelmingly in favour of breaking away from Spain in the poll, although turnout was low amid a boycott by unionists.
The referendum sparked a constitutional crisis in Spain, and the central government responded by suspending the region of Catalonia's government for a spell in autumn 2017.
Most of the 12 separatist leaders have been in pre-trial detention for more than a year.
Prosecutors are seeking a 25-year jail sentence for former regional vice president Oriol Junqueras, while the others - among them former regional ministers and two leading activists - could face between 16 and 17 years in prison.
A total of almost 600 witnesses are to be questioned, including Mariano Rajoy, who was prime minister at the time of the referendum.
The trial, which began on Tuesday, is expected to take at least three months.
Former regional president Carles Puigdemont, who has gone into exile, will not be involved.
On Monday, Puigdemont demanded dialogue between Catalonia and the central government about Catalonia's independence while at the Berlin Film Festival.