Before that came the "Medieval Warm Period", in which temperatures were about the same as they are today.
By matching ring-width patterns in a specimen of known age (starting with living specimens) to ring-width patterns in an older specimen, the proper placement of the older specimen is determined.
The finer weave of 3-over-1 herringbone is consistent with the New Testament statement that the "sindon" (or shroud) was purchased by Joseph of Arimathea, who was a wealthy man.
In 1532, there was a fire in the church in Chambery, France, where the Shroud was being kept.
The University of Arizona dendrochronology lab sports a (no longer living) specimen which contains over 6,000 rings.
Generally, it is not possible to construct a complete sequence of tree rings back through the historical periods using only living trees.