Princess Maria Teresa of Bourbon-Parma died from the new CCP virus, her brother announced.
Teresa, 86, was born in France and part of Spain’s royal family.
She lived in Madrid for most of her life but died in Paris.
She was also known as the “red princess” because of her support for socialist ideas.
“For us, the socialist idea was not the class struggle but the permanent search for consensus,” she said, also claiming that Venezuelan dictator Hugo Chavez “made mistakes” but did “a lot of positive things.”
Teresa was not married and had no children. She is survived by Henry and three other siblings.
Charles, the eldest son of Queen Elizabeth, is showing only mild symptoms and has been working from home, Clarence House said in a statement.
The prince met with Prince Albert on March 10. The latter said in a radio interview that he did not shake hands with the other prince.
The country is one of the hardest-hit in the world. Its official mortality rate of 7.8 percent is only eclipsed by Italy, though authorities in China, Iran, and some other nations are widely known to be underreporting official figures.
France has over 33,000 confirmed cases and nearly 2,000 deaths.