The Constitution of Medina (دستور المدينة, Dustūr al-Madīna), also known as the Charter of Medina (صحيفة المدينة, Ṣaḥīfat al-Madīnah; or: ميثاق المدينة, Mīthāq al-Madina "Covenant of Medina"), is the modern name given to a document or documents believed to have formalized the agreement between Muhammad, his followers, and the residents of Medina. Portions of this constitution are corroborated by multiple sound hadith reports. Its validity in its stated single form, however, has been called into question, as there is no single sound chain of authorities (isnad) supporting it. There are differences of opinion as well as to how many documents the constitution comprises—from one to eight. It is also unclear with which Jews this agreement was made, whether it was only with some of the smaller Jewish social units that had lost their tribal structure and affiliated with the Arabs, with the Judaized Arabs, or also included the three major Jewish clans in the city, namely Banu Qaynuqa, Banu Nadir, and Banu Qurayza.
This constitution gave the Islamic prophet Muhammad, who had just escaped persecution in Mecca, a leading role in the community of Medina. By dating this treaty at the outset of his arrival, it credited Muhammad with honor and power earlier than he would later gain, but more importantly, it gives the justification for Muhammad's subsequent attacks on the Jews as retaliation for their opposition to him. There is a suggestion, however, that if this constitution really existed, it was probably created after the elimination of the three major Jewish clans in Medina by Muhammad and his troops. Others, such as Bernard Lewis, argue that the charter was not a treaty in the modern sense but a unilateral proclamation by Muhammad.
The preamble declares the document to be "a book [kitab] of the prophet Muhammad to operate between the believers [mu'minin] and Muslims from the Quraysh tribe and from Yathrib and those who may be under them and wage war in their company" declaring them to constitute "one community [ummah wāḥidah] separate from all other people".