In 1878, archaeologists excavating the Viking town in current day Sweden, uncovered an ornate 10th-century burial tomb. Containing a full set of weaponry, including a sword, spear, armor piercing arrows and shield, as well as the skeletons of two horses and a game board, archeologists excitedly announced that they had discovered the tomb of a great Viking warrior.
Of course, being the Victorian Era, it was assumed that the warrior was a man.
That story persisted until 2017, when The American Journal of Physical Antropology announced that comprehensive genomic sequencing had revealed that the warrior was, instead, a woman.
Even then, there was a backlash, suggesting mistakes in the sampling and sequencing. A second report, published in Antiquity, confirmed the 2017 conclusion. The author acknowledged that it was extremely difficult to assess aspects such as gender roles and identity from cultures that existed so long ago.