Parties that want Catalonia to split from Spain have won a slim majority in elections.
The vote was held almost two months after the region's parliament was dissolved by the national government for holding a disputed independence referendum.
Following the referendum, regional leaders declared independence.
Madrid subsequently moved to take direct control of the region under a law known as Article 155.
The ousted president Carles Puigdemont has been in self-imposed exile in Brussels - where he spoke overnight.
He told supporters: "I want to congratulate Catalan people because they have sent a message to the world - the Catalan republic has beaten the monarchy and Article 155.
"The Spanish state has been beaten," he added.
While an anti-separatist party won the most seats, Mr Puigdemont's party will be the second largest party in the new parliament with 34 seats.
Two other pro-independence parties won a total of 36 seats between them - which, combined with Mr Puigdemont's party, gives a total of 70.
That is more than is needed for an absolute majority.