In 1968, a weapon grave with brooches was found at Suontaka Vesitorninmäki, Hattula, Finland. Since then, the grave has been interpreted as evidence of powerful women, even female warriors and leaders in early medieval Finland. Others have denied the possibility of a woman buried with a sword and tried to explain it as a double burial. We present the first modern analysis of the grave, including an examination of its context, a soil sample analysis for microremains, and an aDNA analysis. Based on these analyses, we suggest a new interpretation: the Suontaka grave possibly belonged to an individual with sex-chromosomal aneuploidy XXY. The overall context of the grave indicates that it was a respected person whose gender identity may well have been non-binary.