Taewŏnsu (literally grand marshal, usually translated as generalissimo) is the highest possible military rank of North Korea and is intended to be an honorific title for Kim Il-sung and Kim Jong-il. The rank is senior to that of wonsu (marshal).

The rank of taewŏnsu was created by a joint decision of the Central Committee and Central Military Commission of the Workers' Party of Korea, the National Defense Commission and the Central People′s Committee in April 1992 to honour Kim Il-sung on his 80th birthday.

In February 2012, his son and successor Kim Jong-il was awarded the title posthumously on the occasion of his official 70th birthday.

According to rank comparison charts of the United States Forces Korea (USFK), taewŏnsu is equivalent to a "seven-star general", with the junior ranks of wonsu and chasu listed as six and five stars respectively. The rank is frequently referred to in U.S. military publications as "grand marshal", comparable to the rank of general of the armies.

The insignia for taewŏnsu is similar to wonsu but with an added crest worn beneath the shoulder board's large marshal star (and an added crest added to the parade uniform's marshal star worn below the collar), below the Emblem of North Korea. The rank insignia is based on the now obsolete rank generalissimus of the Soviet Union.

If translated, the full rank is "grand marshal of the Democratic People's Republic of Korea" literally and "generalissimo of the DPRK" in the usual translation.

More Info: en.wikipedia.org