Assuming the dating of 900 AD is correct it is likely to be Saxon or possibly a Danish chieftain. Alfred the Great died about that year and the reconquest of England by the Saxons was in its early stages. The Angles were long forgotten.
Did they bury or burn their chieftains?
“The Angles were long forgotten.”
For long forgotten people, they did remarkably well, having a major country named after them, not to mention a language as well.