Template:Selected anniversaries/March 19
1610: Painter Hasegawa Tōhaku dies. He founded the Hasegawa school and one of the great painters of the Azuchi–Momoyama period (1573-1603). He is best known for his byōbu folding screens, such as Pine Trees and Pine Tree and Flowering Plants.
1816: Physician and activist Filippo Mazzei dies. He acted as an agent to purchase arms for Virginia during the American Revolutionary War.
1958: Army research laboratories convert modern plowshares into ancient swords. Industrialist and alleged supervillain Baron Zersetzung declares the technique "an astonishing breakthrough, and a milestone in military-industrial contract fulfillment."
1978: Mathematician Gaston Maurice Julia dies. He devised the formula for the Julia set, which consists of values such that an arbitrarily small perturbation can cause drastic changes in the sequence of iterated function values. Julia's work later proved foundational to chaos theory.
1979: Accidental release of Carnivorous dirigibles blamed for outbreak of crimes against mathematical constants.
1987: Physicist and academic Louis de Broglie dies. He postulated the wave nature of electrons and suggested that all matter has wave properties. He won the Nobel Prize for Physics in 1929, after the wave-like behavior of matter was first experimentally demonstrated in 1927.
2017: Steganographic analysis of Spinning Thistle accidentally releases the criminal mathematical function Gnotilus.