Amīr Tīmūr won the struggle for dominance of the Chagatai society, one of the four parts that emerged after the Mongol Empire was disintegrated. He established his rule-based in Samarkand in the second half of the 14th century. Amīr Tīmūr's struggle with the dynasties formed with the dissolution of Ilkhanid domination in the Khorasan lands, where he expanded his sovereignty after 1370 when he came to power and occupied an important part of his political life. Since Khorasan is an area where Islamic sects spread and settled, it is known as a geography where sectarian conflicts are not lacking and the states establishing administration in the region face problems. While Tīmūr wanted to seize Khorasan to rebuild the Ilkhanid throne, he abolished Shiite dynasties such as Serbedarīs and Marashis and Sunni dynasties such as Kerts and Muzaffarīs. However, he gave an image of supporting Sunnism in his struggle with the Shiites. Similarly, with its harsh attitude towards Hurufis, who originated from Shiism, it did not recognize any movement that it thought was harmful to Sunnism. After capturing the lands of Chaghatay and Īlkhānate, he made expeditions to another Mongolian nation, Altınorda. His campaigns in Anatolia, Syria, and Iraq regions outside the Mongolian zone caused him to come face to face with the states in the area. Based on the practices of Tīmūr, who lost his life in 1405 when he launched his last expedition on China, during his military and political activities, many opinions have been put forward about his understanding of religion and sect. The fact that different interpretations were made due to Tīmūr's personality and religious life and that no study on this subject in the history of sects prompted us to investigate this issue. In this study, we aimed to reveal Amīr Tīmūr's approach to sects and his effects on the political activities he continued throughout his rule. In our study, we benefited from the Zafarnamas of Nizamaddin Shami and Ali Yazdī, who are historians of the Tīmūrid period, and the works of Aja’ib al-Maqdur by İbni Arabshah and the an-Nujum al-Zahirah of the Mamluk Historian Ibn Taghribirdi. We also examined the studies on Feridun Bey Munshaat, in which his correspondence with Sultan Bayezid was recorded. In addition, studies and copyrighted works with the History of Tīmūr were also used. As a result of our examination, it has been seen that Amīr Tīmūr's activities, beyond the religious and sectarian concerns, benefited from all kinds of situations to realize the aim of absolute domination with the influence of the understanding of Turkish and Mongolian sovereignty. While he was seen as the protector of Sunnism against the Shiites in the Khorasan region, he also eliminated the Sunni dynasties in the region. He organized expeditions to the lands of Altınorda, which was also Sunni. Therefore, it is seen that he built the aforementioned regions to unite the Mongol lands directly, not because of the problem arising from any religion and sect. The reason why he abolished the Shiite dynasties in Khorasan and Mazandaran is that they caused problems against the sovereignty of the Shiites. It is understood that he put his political goals on a religious basis by introducing himself as ulū al-amr in his struggle against Sunni dynasties in the Near East, where he launched a campaign for different reasons, such as the Ottoman and Mamluks. Therefore, it is seen that Amīr Tīmūr's military activities were due to political reasons rather than the influence of the Sunni Islam belief. In addition, his support of Sunni scholars and clergy, as well as the Seljuks during his rule, establishing religious offices and bringing Sunnis to these positions, and bringing the Sunni creed to the forefront through the opened madrasas paved the way for the development of Sunnism. In terms of the history of the sects, it has been seen that Ash'arism, which gained strength with the influence of the Nizamiya Madrasahs opened in the Seljuk period, left its place to the Transoxiana-centered Maturidism during the reign of Tīmūr and his successors. * This study was prepared based on the Master's thesis titled “Amīr Tīmūr’s Sectarian Politics based on Sunnism and Shiism”, which was continued under the supervision of Associate Professor Hasan Gümüşoğlu (Yalova: Yalova University, Institute of Graduate Studies, Master Thesis, 2023).