This is a translation of a treatise by Habib `Abdullah bin Husayn bin Tahir (may Allah have mercy upon him and benefit us by him) entitled ‘Reminding Believers of What was Sent with the Best of Messengers.’ Although small in size, the treatise contains a comprehensive summary of the message which the Prophet ﷺ conveyed. Many people have tried and will try to summarise the teachings of Islam, but few have been able or will be able to do so in a way as complete and comprehensive as this great Imam, who combined inward and outward knowledge. May Allah allow us to be included in the prayer of Habib `Abdullah that ‘those who use it as a reminder or disseminate it will be people who commanded the good and forbade evil, and that they be beloved to the Best of Creation.’