This paper aims to explore the speech acts and the modesty of the language politeness principles by Ali bin Abi Thalib in his letters to Muawiyah. In addition, to find out the meaning of using politeness in various speech acts in Ali bin Abi Thalib's letters to Muawiyah, The researcher used speech act theory (Searle) and politeness maxim that was formulated by Leech as the main analysis in this…