26 March: South Korean warship, Cheonan, sinks, killing 46 sailors.
20 May: Panel says a North Korean torpedo sank the ship; Pyongyang denies involvement.
July-September: South Korea and US hold military exercises; US places more sanctions on Pyongyang.
29 September: North holds rare party congress seen as part of father-to-son succession move.
29 October: Troops from North and South Korea exchange fire across the land border.
12 November: North Korea shows US scientist new - undeclared - uranium enrichment facility.
23 November: North shells island of Yeonpyeong, killing at least four South Koreans.
27 Nov-1 Dec: South Korea and US hold joint military drills.
6-12 Dec: South Korea stages live-fire military exercises