Spanish Prime Minister Pedro Sanchez said on Monday his government would pardon nine Catalan separatist leaders jailed for their role in a 2017 independence bid.
Below is a timeline of the key events since the separatist leaders held an independence referendum in Catalonia that had been banned by the courts:
Sept. 6, 2017 - Catalonia's pro-independence head of government Carles Puigdemont announces an independence referendum on Oct. 1 after securing the support of the separatist-controlled regional parliament.
Oct. 1, 2017 - About 2.3 million people - around 43% of eligible voters - turned out for the referendum, which had not been authorized by the courts. Some 90% voted to break away from Spain, according to the Catalan government, while many of those opposed to independence boycotted the ballot. Spanish police wielded batons at crowds attempting to vote.
Oct. 16, 2017 - Spain's High Court ordered the jailing of the leaders of two of the largest separatist organizations, Jordi Sanchez and Jordi Cuixart, on sedition charges.
Oct. 27, 2017 - A majority of Catalan lawmakers - 70 out of 135 - voted to recognize the result of the referendum and declared Catalonia an independent nation. In response, Madrid imposed direct rule on the region, dissolving the parliament and dismissing Puigdemont, who subsequently fled to Belgium.
Nov. 2, 2017 - A Spanish judge ordered the pre-trial detention of former Catalan deputy leader Oriol Junqueras and eight other former regional officials on charges of rebellion, sedition and misuse of public funds.
Dec. 21, 2017 - In regional elections called by Madrid, separatist parties jointly won a narrow majority in the Catalan parliament.
June 2, 2018 - Socialist Pedro Sanchez was sworn in as Spain's prime minister after ousting his conservative predecessor in a confidence vote. Madrid's seven-month direct rule over Catalonia ended the same day with a new regional government sworn in.
Feb. 12, 2019 - The Supreme Court trial of 12 separatist leaders began in Madrid.
Sept. 23, 2019 - Spanish police arrested nine pro-independence activists on suspicion of planning acts of violence to coincide with the Supreme Court verdict.
Oct. 14, 2019 - Spain's Supreme Court sentences nine separatist leaders to prison terms of between nine and 13 years. The ruling triggers mass, sometimes violent, protests in the region.
Nov. 10, 2019 - Sanchez's Socialists win Spain's national election without a majority.
Jan. 7, 2020 - Sanchez forms a minority leftist government with Unidas Podemos and is sworn in as premier. The Catalan separatist, leftist ERC party plays a crucial role in making his government possible, in exchange for talks on resolving the region's political conflict.
Feb. 6, 2020 - Sanchez meets pro-independence regional leader Quim Torra to start wider negotiations with the region.
Sept. 28, 2020 - Spain's Supreme Court upholds a ruling barring Torra from public office, automatically triggering a snap election in Catalonia.
Feb. 14, 2021 - Catalan separatist parties strengthen their majority in the regional assembly and protracted negotiations on forming a government begin.
May 24, 2021 - Left-wing separatist Pere Aragones, from the ERC party, becomes head of the regional government after promising to pursue a strategy of dialogue to win independence from Spain.