Bern:

Bern was occupied by French troops in 1798 during the French Revolutionary Wars, when it was stripped of parts of its territories. It regained control of the Bernese Oberland in 1802, and following the Congress of Vienna of 1814, it newly acquired the Bernese Jura. At this time, it once again became the largest canton of the confederacy as it stood during the Restoration and until the secession of the canton of Jura in 1979. Bern was made the Federal City (seat of the Federal Assembly) within the new Swiss federal state in 1848.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". When did the canton of Jura seceed?
1979