This article examines the emergence of the Basran linguistic school as one of the foundational centers of Arabic grammatical thought and analyzes the contributions of its earliest representatives and their theoretical principles. The study focuses on pioneering figures such as Abu al-Aswad al-Duʾalī and Al-Khalīl ibn Aḥmad al-Farāhīdī, whose works laid the groundwork for the systematic development of naḥw (syntax) and ṣarf (morphology). Particular attention is given to the socio-religious motivations behind the rise of Arabic grammar, especially the need to protect Qurʾānic recitation from grammatical deviation (laḥn). The article further explores the core theoretical principles of the Basran school, notably qiyās (analogy) and taʿlīl (causation), and demonstrates how these methods contributed to the rationalization and codification of Arabic grammar. The findings show that the Basran school did not merely collect linguistic data but established a coherent, normative, and intellectually rigorous grammatical framework that profoundly influenced later Arabic linguistic tradition.