This study analyzes the manuscripts of Piagam Kerinci (Sultan Kerinci charter) and letter stored in the collection of National Library of the Republic of Indonesia. The purposes of this study are (1) to describe the contents of the charter and letters, (2) to explain the development of Islam in Kerinci as reflected on the content of the manuscript, and (3) to reveal the message contained in the manuscript. This study uses a philological approach through historical writing analysis. Several concepts and theories are used as a tool to analyze the historical phenomena studied. The data collected are the Piagam Kerinci manuscripts and letters (three manuscripts) with the code ML 396 D. The study found that the Kerinci Charter, both Charter A, B, and C contain orders to obey Allah and to embrace Islam. In addition, there is an order for the people of Kerinci to establish Islamic syarak (sharia) and leave unruly behaviors in Islam such as: cock fighting, stealing, alcohols, tree/stone worshipping (as of animistic beliefs and practices). The presence of orders in these manuscripts suggests that there was an ideological transformation from animist to Islam belief in the Kerinci community.