This map shows the population size and distribution of villages in Essex after the Norman Conquest in 1086AD.
The plotted data is an extract from the Open Domesday Book.
Total Population of the 1169 Domesday Villages in 1086AD shown is 18605
This would equate to a Fyrd(national service) of approximately 4117 soldiers.
Please Note that the estimate for the Fyrd is based on 25% of the
population(excluding Priests and Slaves) being eligible for military duties.