d.1067, Lady of Coventry and wife of Leofric, Earl of Mercia. Legend first recorded 100 years after her death, by Roger of Wendover. "Peeping Tom" aspect added by 1659.
"glance" (esp. through a small opening), 1460, perhaps alteration of M.E. piken (see peek). The noun was first in sense found in peep of day (1530); meaning "a furtive glance" is first recorded 1730. Peep-hole is from 1681; peep-show is from 1851 (not typically salacious until c.1914). Slang peeper "eye" is from c.1700. Peeping Tom "a curious prying fellow" is from 1796; connection with Lady Godiva story dates only from 1837.