When he heard that, Diomedes’ spirits lifted.
Raising his spear, the lord of the war cry drove it home,
planting it deep down in the earth that feeds us all
and with winning words he called out to Glaucus,
the young captain, "Splendid – you are my friend,
my guest from the days of our grandfathers long ago!
…Come, let us keep clear of each other’s spears,
even there in the thick of battle. Look,
plenty of Trojans there for me to kill,
your famous allies too, any soldier the god
will bring in range or I can run to ground.
And plenty of Argives too – kill them if you can.
But let’s trade armor. The men must know our claim:
we are sworn friends from our fathers’ days till now!"

– Homer

The Iliad, Book 6, lines 253-258, 270-277. This is a very strange meeting on a battlefield. Achaean warrior Diomedes and Lycian army captain Glaucus meet as enemies but end up becoming sworn friends. On hearing the story of Glacus’s heroic grandfather, Diomedes plants his spear in the earth, calls Glaucus his friend and offers to trade armor with him.