The missed one of (if not the) the oldest trees in northern Europe, the Fortingal Yew.
Wikipedia is quoting a very disputed bit of research.
The forestry commission reckons that it's at least 5,000 years old.
The growth habit of the Yew means that tree ring dating isn't possible, and the other methods are contentious.
It is at least 2,000 and might be one of the first to root after the ice melted so potentially c9,000 years old.
If measured at the outermost circumferance then the extreme age is possible.
http://www.forestry.gov.uk/forestry/INFD-6UFC5F
Fascinating things
cheers,
M