The First Global Era (1870-1914) was not just about the Royal Navy securing the sea-lanes and the pound sterling towering over the international financial system. Rule Britannia, with all its explicit power relationships, rested as well on a wealth of private rules and self-governed institutions that made global trade reasonably secure and stable. While this private side of hegemony has been well identified for a long time, the actual construction of global markets, from a micro-perspective, remains largely unexplored – at least, when one looks beyond finance. The present contribution is based on the (as yet unexplored) archives of the London Corn Trade Association (LCTA), a rather small, non-profit, elite association that drafted and implemented the rules for the global cereal markets. From 1878 onwards, this asked that it did three main things. It adopted and updated grain standards, which transformed mere farm produces into globally traded commodities. It arbitrated disputes between merchants, an activity that earned its principals a substantial income flow. And it drafted and continuously amended tens of Standard Contracts that were offered to merchants worldwide. Standard Contracts established in general the market rules: there was no other forum where an adhesion to collective rules and the possibility of sanction were written down...