From http://www.stratsplace.com/martin/no...ia_afgani.html

The 'Little Optimum' - Mediaeval global warming - Leafing through the
fascinating book, The Year 1000, I came across the following snippet, 'The
Normans' Domesday survey of 1086 listed no less than 38 vineyards in
England... the years 950 to 1300 were marked by noticeably warmer
temperatures than we experience today... Meteorologists describe this
mediaeval warm epoch as the 'Little Optimum'... [when] London enjoyed the
climate of the Loire Valley...' By Robert Lacey and Danny Danziger,
paperback, published by Abacus, London, 2000.

Cheers!

Martin