Provided by Dr. Patrick Woodland

Patrick writes:

I had a look in David Hey, The Oxford Companion to Local and Family History 
(1996), p. 275, which starts:

'A tax for a specific purpose, e.g. to subsidize a foreign war, which was 
distinguished from taxes levied on the clergy.  The lay subsidy rolls of 
1290-1334 are a major source for the local historian and for those who are 
interested in the origins of surnames.  The tax was commonly known as the 
Tenth or Fifteenth because it was levied on one-tenth of movable property in 
a town and one-fifteenth of similar property in the countryside.  Movable 
property was chosen for the assessment because wealth was no longer 
concentrated in the ownership of land.

The records are held at the Public record office under E 179. Some county 
record societies have published their fullest returns...'

Hey goes on to talk about exempted poor, evasion, etc.  The most important 
assessment seems to be that of 1334, an edition of which has been published 
by R. E. Glasscock. After 1334 these subsidies fell out of use but were 
revived by Henry VIII - the last one to be of use to local and family 
historians was that of 1546.

By the look of things prominent families can be identified and some 
comparative analysis of the wealth of different communities is possible using 
these records, but 'large numbers were too poor to pay the tax'.