Sal Bertucci wrote:That is total BS! As far as I can tell the first use of the term "Martial Art" was coined by Joseph Sotheby of Grayse-Inne. in his dedicatory poem entitled "To his worthy, valourous, and ingenious friend the Author" found on page 24, line 6.
A book that was printed in 1639!
I hope that's enough info for a reference.
According to my
The Barnhart Concise Dictionary of Etymology: The Origin of American English Words the word Martial is from "About 1339
marcial; later
martial (before 1475)" and goes on to mention its originates from Latin and also says that the term "Martial Law" was first recoded in 1533. Additionally it says that Art though first appearing around 1250 was not used to describe skills before 1600.
The fact that the core word was recognizable as early as the 15th century and was written in conjunction with the word Law(which dates from circa AD 1200) just a century before and the word Art being applied to skills circa 1600 matches up very well with "Martial Art" being first used in writing in 1639 as you said. It could likely have come into use in the spoken word in the decades immediately preceding that first known printing.