From the prince-bishopric to Bern (1815). For about eight centuries the Jura had been part of the Prince-Bishopric of Basel, with the prince-bishop's residence in the castle of Porrentruy. In 1815 the Congress of Vienna assigned its seven districts to the Canton of Bern, as compensation for the loss of Vaud and Aargau. It was the union of a French-speaking and largely Catholic region with a German-speaking, Protestant canton.
The Moeckli affair (1947). In September 1947 the Bernese Grand Council refused to entrust the public works department to the Jura State Councillor Georges Moeckli, on the grounds that he was French-speaking. The affront set off the autonomist movement: on 30 November 1947 the Jura Separatist Movement was founded, later the Rassemblement jurassien, led for decades by Roland Béguelin.
The years of embers (1962–1970). In 1962 young separatists founded the Groupe Bélier, which alternated demonstrative actions with violent acts, up to a few arson attacks. In 1964, at the commemoration of the military mobilisation at Les Rangiers, the federal and Bernese councillors were booed and forced to break off their speeches. On 1 March 1970 the Bernese people agreed to write the possibility of a plebiscite in the Jura into the cantonal constitution.
The plebiscites (1974–1975). On 23 June 1974 the voters of the seven districts answered the question «Do you want to form a new canton?». The yes won with 51.9 per cent, 36,802 votes to 34,057, with a turnout of 88.7 per cent. The northern districts, Delémont, Porrentruy and Franches-Montagnes, voted overwhelmingly yes; the southern ones no. In 1975 further votes allowed the southern districts, Courtelary, Moutier and La Neuveville, to remain Bernese, and the border municipalities to choose which side to be on. The German-speaking district of Laufen would move to Basel-Landschaft in 1994.
The twenty-sixth canton (1977–1979). On 20 March 1977 the people of the Jura approved their constitution. On 24 September 1978 the Swiss people accepted the creation of the new canton with 82.3 per cent of the vote and the approval of all the cantons. On 1 January 1979 the Republic and Canton of Jura became sovereign, with Delémont as its capital. Since then the Fête du peuple jurassien has commemorated the 1974 plebiscite every year on 23 June.
Moutier, the last chapter (2017–2026). The question remained open in the Bernese Jura. In 1996 the small municipality of Vellerat moved to the Jura. Moutier voted to change canton on 18 June 2017, by a margin of only 137 votes, but the vote was annulled for irregularities. On 28 March 2021 it voted again, and this time the yes won with 54.9 per cent. After approval by the peoples of Bern and the Jura in September 2024, Moutier joined the Canton of Jura on 1 January 2026.