Norwich's population at the time of the Domesday survey was probably in the region of about 5,000–10,000 souls. By 1311, the figure was closer to 15,000–17,000, rising again (despite famine in the early fourteenth century) to about 25,000 in 1333. Following plague epidemics in 1349–50, 1369 and 1375, the estimated number of residents in 1377 (extrapolated from poll tax returns) was closer to 7,500–8,000, although influxes of rural immigrants helped to make good earlier losses. Levels subsequently stagnated. Countrywide, the population was at its nadir in 1450, recovering only slowly. An estimated minimum population of 8,500 in 1525 has been suggested on the basis of the subsidy of that year. More recently, this figure has been revised upwards to c. 11,000– 12,000. During the period from the 1530s to 1550s, numbers again fluctuated according to the contrary effects of inward migration and plague or other epidemics, although by the early 1560s, the population probably stood again at the 1525 level. On the subsequent arrival of c. 5,000 Dutch and Walloon immigrants from 1565, who were invited to settle in the city by the authorities in order to bolster the flagging textile industry, see the epilogue to the main text.