He spent his childhood in Italy, where pretty much everyone assumed he was a girl—a misconception that stuck around for years. He worked in Austria's household alongside Hungary, who basically acted as a mother figure to him. Austria, not realizing he was actually a boy, insisted on dressing him in dresses. Hungary was different though—she knew exactly what he was, but dressed him in her traditional women's clothes anyway, which made for an interesting dynamic.
The Holy Roman Empire was another person fooled by his appearance and fell hard for him. Eventually the Holy Roman Empire went off to war and never returned, but creator Hidekaz Himaruya has promised fans that their story will get a happy ending eventually.
Content compiled by AnimeList.moe from publicly available sources.