A monpolist in the highly profitable saltpetre trade (one of the most important commodities in the export list of the European companies) since 1753, this Armenian merchant conducted most of the negotiations between the Company and Nawab Siraj ud-Daulah.
The trades mentioned in the board of ordnance list and in (1815) include the following: carpenter, cooper, millwright, master mixer, refiners of brimstone (sulphur), charcoal, and saltpetre, press-house, corning house, glazing house, dusting house men, sawyer, shave cleaver.
Under Vijayanagara Rayas, Rayara Hubli grew as a commercial centre, famous for trade in cotton, saltpetre and iron.
A small graveyard east of the church, in which excavations have unveiled remains of coffins and bones, is said to have been ravaged by King Gustav Vasa who was looking for raw material for his saltpetre production, a deed commented in the chronicles as Ej är kristeligt i väder så skjuta sina förfäder ("Not Christian is in public thus shoot/push one's ancestors").
Saltpetre and brass utensils are traditionally manufactured in this city.
The fire took place in July 1794 when a smaller fire ignited a barge loaded with saltpetre.
This resulted in an improved method of extracting saltpetre and consequently higher quality gunpowder.
According to Buchanan, the most important occupation of the Telugu Upparas at the beginning of the nineteenth century was the manufacture of earth-salt and saltpetre (an important ingredient in the manufacture of gunpowder).