Born on This Day: April 15

Italian artist, engineer, and investigator whose work united art, anatomy, mechanics, and scientific observation.

Swiss mathematician whose discoveries and notation shaped analysis, number theory, mechanics, and nearly every branch of modern mathematics.

American-British novelist whose psychological insight and narrative technique profoundly influenced modern fiction.

French sociologist whose studies of institutions, solidarity, and social facts helped establish sociology as a discipline.

American singer whose power and emotional range made her a foundational figure in blues and popular music.

North Korean founder and leader whose rule established the country’s enduring political system and international posture.

American actor whose television work became influential in comedy, fantasy, and portrayals of women’s independence.

British actor and screenwriter whose performances and scripts have influenced modern film, drama, and literary adaptation.