October Yushin
President Park declared martial law, dissolved the National Assembly and introduced the Yushin constitution, concentrating power in the presidency.
경향신문사 · Public domain · Source
On 17 October 1972 President Park Chung-hee declared nationwide martial law, dissolved the National Assembly and banned party activity. After a referendum in November, the Yushin constitution was promulgated in December.
Under it the president was elected indirectly by the National Conference for Unification for a six-year term with no limit on re-election. The president held emergency-decree powers and the power to dissolve the Assembly, and nominated one third of its members for election by the Conference (the Yushin Political Fraternity). The president controlled the legislature, judiciary and executive alike.