Ludwig Bemelmans (1898-1962) was an Austrian-born writer and illustrator, naturalized in the United States in 1918. He led a colorful life, working in hotels and restaurants, consorting with gangsters, and joining the US army, as a non-combatant.
Though famous for his children's books featuring Madeline, Bemelmans was exceedingly prolific and wrote numerous books for adult readers, both fiction and non-fiction.
His books are collectable on account of their charming illustrations done in a naive style reminiscent of the work of Raoul Dufy (disclaimer: not that there is anything naive about Dufy's art).
He travelled widely between the wars, and his books also furnish interesting accounts of daily life in the countries of Europe, written by a sympathetic exile.
Above illustrations from The Blue Danube (New York, Viking Press, 1945).