Maximilian goes back to the Roman name Maximilianus, derived from Maximus, and means "greatest". Emperor Maximilian I of the Habsburgs made it a royal name in the 15th century, and Maximilian of Mexico briefly ruled from 1864 to 1867. In the United States the long form offers the nickname Max with a grand full name behind it; it has been in the top 1000 since 2000, peaked at number 429 in 2013 and ranks number 590 in 2025.