Dendrochronology raises questions about the nature of the AD 536 dust-veil event

New evidence is presented which shows the response of a wide grid of tree-ring chronologies to the dust-veil of AD 536, the effects of which were historically recorded in the Mediterranean and eastern Asia. The tree-ring evidence, particularly that from European oaks (Quercus), shows a two-stage response which raises questions about whether only a single massive eruption was involved. The observations from precisely dated tree-ring series set the agenda for the interpretation of forthcoming ice-core evidence across the AD 530s and 540s.