Head over heels
Often used in the context of falling in love but the expression started off, more logically when one thinks about it, as heels over head. It describes of course a fall when one might end up topsy turvey or arse over tit. Earliest known citation for heels over head is by Gaius Valerius Catullus (c. 87-54 BC). The first citation of the inverted, more common form head over heels is found in Contemplative Man (1771) by Herbert Lawrence, “He gave him such a violent in voluntary kick in the face, as drove him head over heels.”