Woolmonger

[…]and the Clothier is made Creditor in Account for ſo much as he ſold for to the ſaid Merchant, then ſuch Cloathier having occaſion to pay money to a Stapler or Woolmonger for Wool, he doth buy of him, ſo the said Clothier is made Debtor, and the Woolmonger Creditor in Account: the ſaid Woolmonger hath bought his Wool of a Countrey Farmer, and muſt pay him for it, ſo the Woolmonger is made Debtor, and the Farmer Creditor:[…]

Source: wiktionary

In 1264, the besieged city was taken by the stratagem of Sir J. Giffard, and Sir J. de Balun, who gained an entrance at the west gate, disguised as woolmongers, then throwing off their large Welsh cloaks, and appearing in complete armour, the terrified wardens delivered up the keys;

Source: wiktionary

Because the woolmongers and usurers are not directly in the hands of the millowners; but the working men are.

Source: wiktionary

Merchants were common among the early Londoners of Suffolk origin, especially mercers (a dozen), burellers, pepperers, woolmongers, vintners, skinners.[…]The export of wool was largely carried on via London, and many woolmongers would find it convenient to settle there.

Source: wiktionary