In 1940, Crown Princess Märtha and her family were immersed in World War II as Germany invaded Norway.

After escaping to her home country of Sweden, and then being evacuated to America by President Franklin D. Roosevelt, she effectively advocated for Norway and did fundraising until the end of the war.

In 1942, King Haakon VII of Norway, Märtha's father-in-law, invested her as a Dame Grand Cross of the Royal Norwegian Order of Saint Olav.

Märtha was born at her parents' home of Arvfurstens Palats in Stockholm on 28 March 1901, the second child of Prince Carl of Sweden, Duke of Västergötland, and his wife Princess Ingeborg of Denmark.

[2] As a child, Märtha was taught at home by private tutors and completed in-depth courses in childcare and first aid.

[1] Tragedy struck Crown Princess Märtha in 1935 when her sister, the Queen of the Belgians,[5] was killed in a car crash; the two siblings had been very close.

In 1938 upon the death of her mother-in-law, Queen Maud, Crown Princess Märtha became the royal Norwegian court's senior lady.

[6] During the flight from the German invasion in 9–10 April 1940, the Norwegian government decided that the Crown Princess and her children were to flee across the border to her native Sweden while her husband and father-in-law remained.

In August 1941, Crown Princess Märtha traveled with President Roosevelt aboard the presidential yacht, USS Potomac, and sailed to Newfoundland and the Atlantic Charter meetings with Winston Churchill.

[6] Her work to assist the American Red Cross and on behalf of Norwegian interests greatly impressed Roosevelt and influenced his "Look to Norway" speech in 1942.

[8] Roosevelt's son James stated that "There was no question that Martha was an important figure in Father's life during the war ... there is a real possibility that a true romantic relationship developed between the president and the princess.

'"[10]Princess Märtha spent much of World War II in the United States, where she worked tirelessly to keep up support for Norway among the American public and government.

She wholly embraced her role as Crown Princess of Norway and made tremendous efforts towards ensuring the stability and well-being of all Norwegians.

[1] Following a lengthy period of ill-health, Märtha died at The National Hospital in Oslo on 5 April 1954 and was buried at Akershus Castle.

[12][13] Her death came while her elder daughter Princess Ragnhild was expecting her first child and just over three years before her husband ascended the throne as King.

[15] Märtha is depicted in the historical docudrama television miniseries Atlantic Crossing, a co-production of Cinenord and the state broadcaster, NRK.