During this period, he emerged as an active journalist and teacher in the labour movement, and became acquainted with the leadership of the Social Democrats and the trade unions.

[1] During the Nazi occupation, Krag worked as a civil servant in a Danish government agency and became a leading economic advisor to the labour movement, as well as a protégé of prominent social democrat and future prime minister Hans Hedtoft.

In 1950, Krag resigned from Parliament partially due to a conflict with Vilhelm Buhl and H. C. Hansen and, in order to become more fluent in the English language and see more of the world, requested a position at the Danish embassy in the United States.

In September 1962 he succeeded Viggo Kampmann as prime minister and leader of the Danish Social Democratic Party.

Less than a year into his first term as prime minister, the opposition held a referendum which rejected a set of land laws already passed by Krag's government.

In social policy, a number of progressive reforms were implemented during Krag's time as prime minister.

[3] while A law passed in June 1972 introduced a new scheme for daily cash benefits in cases of sickness and maternity.

The couple had two children, Jens Christian (son) (born 1960) and Astrid Helene "Søsser" (daughter) (1962–2014), as well as another child outside of wedlock (Peter Hansted).

He managed to raise Denmark's profile on the world stage, striking up strong relationships with fellow European leaders as well as American presidents Kennedy and Johnson.

His list of political achievements is also one of the most impressive, overseeing one of the longest periods of economic expansion in Danish history.