But the full significance of what his burial contained would take decades to understand.

What Dendrochronology Told The Investigators

One of the most powerful tools available to medieval archaeologists is dendrochronology: the science of dating wood by analyzing the pattern of annual growth rings preserved in timber.

Trees grow a new ring of wood every year.

The width of each ring reflects growing conditions: a wet, productive year produces a wider ring; a dry, stressful year produces a narrower one.

Because these patterns are regional and consistent, researchers have built reference chronologies for different tree species in different parts of Europe, stretching back thousands of years.