Robert Baden-Powell, 1st Baron Baden-Powell

Robert Stephenson Smyth Baden-Powell joined the British Army in 1876 and served in India and Africa until 1910, rising to Lieutenant-General. His 1899 defense of Mafeking during the Second Boer War made his name, but his reconnaissance handbooks - Aids to Scouting chief among them - had a stranger afterlife: teachers and youth groups began using them with boys. In August 1907 he ran an experimental camp on Brownsea Island to test whether his scouting methods could work for civilians, then published Scouting for Boys the following year. It spread fast. By 1909 girls in Scout uniform were showing up at rallies, declaring themselves "Girl Scouts"; Baden-Powell and his sister Agnes formalized The Girl Guides Association in 1910. He retired from the army that same year to lead the movement full-time, married Olave St Clair Soames in 1912, and guided both organizations until stepping back in 1937. He spent his final years in Nyeri, Kenya, where he died in 1941 and was buried beneath what became a national monument.