Benjamin Royall was listed in Chase’s Directory of 1783 as a millwright at 15, Tooley St. In 1791 he was expanding into another area of business.

Mr. JOHN LARK, of the flower-in Hand, St. Mary’s, having declined the above business, BENJAMIN ROYALL, Millwright, of the aforesaid parish, does hereby solicit the continuance of the favors of Mr. Lark’s friends, as they rest assured of being supplied with neat carriages and good horses on the earliest notice, and their favours gratefully acknowledged by their humble servant,

B. ROYALL

The Carriages and Horses continue at Mr. Lark’s Stables.
Norfolk Chronicle - 9th April 1791

On Saturday, the 11 th inst. at eleven o'clock in the forenoon, at BENJAMIN ROYALL’S Millwright, in St. Augustine’s Norwich. Two Pair of FRENCH BURR STONES, 4½ feet in diameter, with Irons and Vats belonging thereto; 55 French Stones, three Flour mills, One cylinder, one Rolling Screen, and several other articles in the Flour Mills.
Norfolk Chronicle - 4th April 1801

At his Great room, at the Dove, in St. Lawrence, on Thursday the 19th day of May instant, at five o'clock in the afternoon precisely, subject to such Conditions of Sale as will then be produced.
A most desirable Situation for a wheelwright, Carpenter, Blacksmith, Bricklayer, Millwright, or any trade where room is required; consisting of a very good Dwelling-house, principally new-built, now used as a public-house, with two tenements adjoining, fronting the street, situated at St. Mary at Coslany, in Norwich, together also with a large yard at the back thereof, with stables, workshops, blacksmith’s shop, founder, and all other requisites conveniences for carrying on the millwright business, as the same are now in the occupation of Mr. Benjamin Royall, Millwright, and his undertenants.
The above freehold, very moderately assessed to the Land-tax, and will produce a net annual rental of 20l. a year. For further particulars apply to Mr. Marsh, Bank-street, Norwich.
Norfolk Chronicle - 14th May 1803