There are frequent references in the Liber Albus and the City Letter Books to the sale of corn at "Graschirche" during the 14th and 15th centuries, and it appears from a proclamation of 1374 that there was a regular market held there at that time, for it was provided in the proclamation that those who brought corn to the City for sale from Cambridgeshire and the neighbouring counties should take their corn to be sold "a la Marche sur la Pavement a Graschirche" (Lib. Albus I. 433, and Cal. L. Bk. G. p. 330).
The market must have been held by St. Benet Gracechurch at the junction of Gracechurch Street with Fenchurch Street and Lombard Street, and from Lib. Albus I. 247, it appears there was a regular scale of customs levied on the corn, etc., brought to "Gerchirche" or "Graschirche" for sale.
The existence of such a market for hay, corn, etc., in early times suggests the derivation of the names of some of the neighbouring churches and streets "Graschirch," "Fanchurch," from O.E. "gaers," "gers" = a blade of grass, herb, hay, and L. "faenum" = hay.
Stow speaks of a Herb Market there (S. 214).
A Dictionary of London. Henry A Harben. 1918.