In medieval times, a person issued a challenge by throwing their gauntlet (glove) to the ground. Whoever picked it up was deemed to have accepted the challenge.
RELATED IDIOMS :
run the gauntlet
go through an intimidating or dangerous crowd, place or experience in order to reach a goal.
This phrase alludes to the former military practice of punishing a wrongdoer by forcing him to run between two lines of men armed with sticks, who beat him as he passed. Gauntlet here has nothing to do with a glove, but is a version of an earlier word gantlope, itself taken from Swedish gatloppe which meant lane course.