They go on trial on Tuesday to face charges related to the illegal independence referendum in October 2017.
Here is our round-up of key European stories so far today, Wednesday, February 6.
Our weekly round-up brings you all the opinions that have been driving debate across Europe and further afield over the last seven days.
"What would the effect on the EU’s democratic credibility be if ... secessionist politicians were not tried, after circumventing the basic foundations of democratic rule of law in Spain?"
We bring you our weekly View round-up of all the opinions driving debate across Europe and further afield.
Leaders of the 2017 Catalan independence referendum are facing a combined total of 217 years in prison for inciting rebellion. Defending their rights is in the self-interest of Europe if it wants to remain a leading force for democracy.
Spain’s trail of the century begins tomorrow, as 18 leading Catalan separatists will face prosecution for their role in Catalonia’s unilateral declaration of independence from Madrid.
The Catalan independence movement is just one of the many obstacles facing a push to modernise the Spanish Constitution. In order to make sure it serves the needs of all Spaniards today, we have to solve our long-standing problems first.
Two more separatist Catalan leaders have joined the hunger strike in Spain.
Protestors claim government too conciliatory
Jailed leaders Jordi Sanchez and Jordi Turull played a part in Catalonia's failed bid for independence last year, and have gone on hunger strike to 'raise awareness' of unfair treatment by Spain ahead of the trial.
Spanish auditors have ordered former Catalan leader Artur Mas and nine others to repay €4.9 million of public money spent on a non-binding independence vote in 2014.
Separatists claim intimidation and provocation from police who are engaged in a pay dispute with Madrid.
Catalan independence and European values: Uncut with Carles Puigdemont
Former Catalan leader Carles Puigdemont has been speaking exclusively to Euronews.
Riot police broke up a demonstration in Barcelona after tens of thousands of Catalan independence supporters protested, a year on from the vote deemed illegal by Madrid.
On the one-year anniversary of the banned independence referendum, triggering one of the biggest institutional crises in Spain, where are its protagonists? Has the Catalan pro-independence movement lost its power?
Clashes police march for higher wages were blocked by Catalan separatists one year on from the referendum.
Hundreds of thousands march in Barcelona for the annual festival, which has become representative of the independence movement in Catalonia.
Catalan politicians attending national day celebrations reaffirm their support for independence and say meaningful negotiations with Madrid over the issue can only take place after jailed colleagues are freed
Catalonia celebrates "La Diada" today, and separatists are marking the occasion with a show of strength in the streets. It's the first National Day since the region declared independence last year and kicked off constitutional chaos.
On September 17, Belgian judges will rule on whether the controversial Spanish rapper Valtonyc may be extradited back to his native Spain, where he has been sentenced to three and a half years in prison for "glorifying terrorism".
Ex Catalan leader Carles Puigdemont returned from Germany to Belgium on Saturday after Spain failed in an attempt to extradite him from Germany on charges of rebellion over an illegal declaration of independence.
Spain withdraws international arrest warrants against Puigdemont and other Catalan politicians.
Spain marks civil war anniversary amid a rise in nationalism