In the years immediately following the publication of Cuningham's plan (1559), life in Norwich underwent a series of marked developments. Specifically, the city experienced a social revolution. In 1564–65, Dutch and Walloon textile workers were invited by the corporation to settle in Norwich in order to stimulate its flagging textile manufacturing sector. From an initial few hundred, the number of incomers had risen to 4,000 by 1571, an increase of about thirty-five per cent of the size of the population of the time. On occasion, the new arrivals were treated with outright hostility by individual citizens, whilst the attitude of officers in the corporation also seems to have been ambivalent. Thus, when a devastating outbreak of plague hit the city in 1578, the ‘Stranger’ community received much of the blame for aggravating it through allegedly unhygienic practices: a lack of domestic cleanliness – including the ‘corrupte kepinge of … howses and necessaries [prives]’ – was one issue; industrial pollution was another. The assembly recognized that the processes of scouring woollen baize in the river were ‘bothe daungerous and very onholsome in eny tyme, but most [of all] in the Somer tyme and in the tyme of syckenes’ (thus tacitly recognizing that practices which might be generally tolerated were irresponsible at riskier times of the year). In late March 1579, it placed a ban on the scouring of cloth within the river or waterways in central parts of the city. The mayor of Norwich also wrote a letter to the Dutch and Walloon congregations demanding that the new arrivals implement much tighter controls on the disposal of effluent. Henceforth, the letter requested, the Strangers must take care to sluice away by-products accruing from the treatment of wool (an important part of their industrial activities), because the fumes would otherwise ‘breede in … bodies dyvers corrupte humours, to the great daunger of their bodies in this infectious time’. The dust and other material produced by combing wool and ‘chamber wash’ were also identified as agents infecting the air. From then on, chamber wash was not to be conveyed anywhere for disposal during the day, but only at night, and then only ‘in a close tubb or elles coveryd with a clothe’; likewise, wool combing was not to take place ‘towardes the open strete’ but ‘inwardly in backehowses’, out of harm's way.