The Sidyadoni inscription of the Pratihara period provides valuable information about the categories of merchants during that time. Among the various categories mentioned, the most important one according to this inscription is the grain merchants.

The inscription refers to the grain merchants as "Annapāṇikas" which indicates their significance in the economic and social fabric of the society. Let's delve into the reasons why grain merchants were considered the most important category during the Pratihara period.

1. Economic Importance: Grain was a staple food and formed the basis of sustenance for the majority of the population. Grain merchants played a crucial role in the distribution and trade of this essential commodity. They ensured a steady supply of grains to different regions, contributing to the overall economic stability.

2. Social Significance: As the main suppliers of food grains, the grain merchants held a position of influence in society. They were responsible for meeting the basic needs of the people, which gave them considerable power and authority. Their ability to control the availability and pricing of grains made them vital figures in the societal structure.

3. Political Influence: The inscription also mentions that the grain merchants had close connections with the ruling elite. Their economic prominence allowed them to establish political alliances and exert influence over decision-making processes. Their support was sought after by the rulers, further highlighting their importance.

4. Market Regulation: The grain merchants were responsible for maintaining the stability of the grain market. They ensured fair trade practices, monitored quality standards, and regulated prices, preventing exploitation and ensuring the availability of grains to all sections of society.

5. Trade Networks: Grain merchants played a pivotal role in establishing and expanding trade networks. Their business activities involved transportation, storage, and distribution of grains across different regions. Their networks facilitated the exchange of goods and services, contributing to the economic growth of the region.

In conclusion, the Sidyadoni inscription of the Pratihara period highlights the significance of grain merchants as the most important category of merchants during that time. Their economic importance, social significance, political influence, market regulation, and trade networks established their prominence in the society of that period.