For several years, my sword training has focused on the one-handed longsword style most popular in italy and germany during the renaissance, but my brother keeps arguing with me that any fighting technique that left one hand free, without use of a shield or main gauche or anything to the effect, was inefficient in battle, and historically not used for anything more than sport. he will never listen to my side of the argument from personal experience... what are some historic examples of one-handed warfare i can show him to support my point?
Please do not take offense but your brother needs to do a little homework in both Western Martial Arts and history. I would suggest taking your question here http://www.swordforum.com/forums/forumdisplay.php?15-Historical-European-Swordsmanship . Most of the major HEMA/HES/WMA instructors post there and you will get tons of information regarding your question.