Who is Jack of the Lantern?

There is plenty of folklore to explain why we carve pumpkins and put lights in them.  According to Mirriam-Webster: the term jack-o’-lantern has been used in American English to describe a lantern made from a hollowed-out pumpkin since the 19th century, but the term originated in 17^th century Britain, where it was used to refer to a man with a lantern or to a night watchman. At that time, the British often called men whose names they didn’t know by a common name like Jack. Thus, an unknown man carrying a lantern was sometimes called “Jack with the lantern” or “Jack of the lantern.”