Newborough Anglesey Universal British Directory 1791

Newborough, or Newburgh, is distant from London 254 miles, situate over against Caernarvon in North Wales, about 17 miles south-west from Beaumaris. This small town is governed by a mayor, two bailiffs, and a recorder. Its Welch name is Rhôssir, or Rhosvair. Its weekly markets, which are pretty well supplied with provisions, are kept on Tuesdays; and its annual fairs on 22nd of June, Aug. 10 and 21, Sep. 25, and Nov. 11.

Source: The Universal British Directory of Trade, Commerce, and Manufacture 1791. Vol. 5.