1. The first time someone got a wedgie: A.D. 96
Whenever you get up out of your chair
(I often have been noticing it now),
your wretched tunic sodomizes you.
And when you go and try to pluck it out
—now straining with your right hand, now your left—
you only work it out with groans and tears,
so crushed is it between the Syplegad-
ianic rocks of your great fundament,
so trapped between the rocks Cyanean
of your excessive buttocks…
2. The first time someone yelled “look behind you” as a trick: ca. A.D. 1000
Aife challenged Cúchulainn to single combat. Cúchulainn went up to Scáthach and asked her what Aife held most dear above all else.
“The things she holds most dear,” Scáthach said, “are her two horses, her chariot and her charioteer.”
Cúchulainn met and fought Aife on the rope of feats. Aife smashed Cúchulainn’s weapon. All she left him was a part of his sword no bigger than a fist.
“Look! Oh, look!” Cúchulainn said. “Aife’s charioteer and her two horses and the chariot have fallen into the valley! They are all dead.”
Aife looked round and Cúchulainn leaped at her and seized her by the two breasts. He took her on his back like a sack, and brought her back to his own army.
3. The first time someone swapped urine to fool a urine test: 1176
And her nurse stays near her, who with very wondrous craft sought secretly through all the town, so that no one knew it, until she found a woman sick of a mortal sickness without cure. In order the better to carry out the deception, she went often to visit her and promised her that she would cure her of her ill, and each day she would bring a glass to see her water, till she saw that medicine would no longer be able to aid her and that she would die that very day. She has brought this water and has kept it straitly until the emperor rose. Now she goes before him and says to him: “If you will, sire, send for all your leeches, for my lady, who is suffering from a sore sickness, has passed water and wishes that the leeches see it, but that they come not in her presence.” The leeches came into the hall; they see the water very bad and pale, and each says what seems to him the truth, till they all agree together that never will she recover…
4. The first time someone compared poop to a turtle’s head: 1573
To relieve yourself, it is necessary to hang out over the sea…many times the turd that has begun to emerge, for fear of falling into the sea, retires and returns inside like the head of a tortoise…
(From Eugenio de Salazar’s letters. Translation by Carla Rahn Phillips.)
(These “firsts” are not authoritative, of course, because an earlier text could always show up; corrections (i.e. earlier attestations) as well as examples of other firsts are extremely welcome.)