My all-time favorite:
When the last of the Teutonic knights were defeated and dispersed at the Battle of Tannenberg, one group of men, broken and cut off, fled north. Arriving at the gulf of Bothinia, the reasoned that they could not return to their hometowns to face ridicule or further persecution. Instead they felled some nearby trees to build rafts, intending to sail across to new lands where they might start a new life, perhaps as a mercenary band or other military service to whatever lords or kings they met over there.
Two sets of items they brought with them: their banded plate armor, so that the people they met would know they were men at arms and of at least some means and wealth, and trencher plates. Shallower than a bowl, deeper than a platter, a trencher would hold whatever foreign food stuffs they were served - solids portions, stews or soups.
And off they sailed. But the day afer their first night at sea a terrible storm arose. The waves washed higher, waterlogging the rafts, and with the weight of their armor, they foundered and all men were lost.
Nowadays, modern oceanographers have found the remains of that failed expedition, which is why we can know today that:
"Plate Teutonics are responsible for the rafts and trenchers found on the ocean floor."
