As a surname, Cannon only goes back to the early to mid Middle Ages, when surnames were in general being formed in English-speaking countries.
As a given fn, the very earliest Cannon would've probably been used would be about the 16th century, when it could've been a mother's maiden name transferred. However, it's more likely that Cannon would've started to be given in the Victorian Era
, when surnames for boys was quite trendy (and the surname didn't have to have a familial connection, either).
But, most will see Cannon as a given name to be quite trendily 20th-21st century. Indeed, if you click here, you'll see just how modern the name is popularity-wise: http://snipurl.com/da22
"Multiple exclamation marks are a sure sign of diseased mind" -- Terry Pratchett
!!!!!!!!!! ← Maud, John, Alice, Peter, Emma, Edith, Lewis, Henry, Isabel, and Joseph