The commissariat was the main economic drivers in the colonial economy between 1788 and 1835. It is not frequently discussed in the literature and it was Professor N. G. Butlin who challenged economic historians to write the story of the commissariat in operation. This thesis relates the story of the role and operations of the commissariat in colonial NSW. The commissariat filled many roles, ranging from government store, to financial services provider and a quasi-treasury. It was the main purchaser of local production from local settlers, and offered a novel and creative 'barter system' by exchanging store receipts for goods and services received from local settlers