Maximillian is a double-l spelling of Maximilian, from the Latin Maximilianus, which rests on maximus, "greatest". Tradition has it that Emperor Frederick III coined the name for his son, the future Habsburg emperor Maximilian I, by fusing the Roman names Maximus and Aemilianus. This spelling ranked number 720 in the United States in 2000, left the top 1000 in the years that followed and stands at number 1845 in 2025.