The doctrine of Imamate in Imami Shiʿism underwent a fundamental transformation during the second half of the third/ninth century, coinciding with the Minor Occultation (al-Ghayba al-Ṣughrā). Following the martyrdom of Imam al-Ḥasan al-ʿAskarī (a), the Imami community faced a crisis of succession and the emergence of competing intellectual currents, including the Neo-Wāqifa, Jaʿfariyya, and Muḥammadiyya. Within this intellectual milieu, ʿAlī b. Muḥammad ʿAllān al-Kulaynī al-Rāzī (fl. 279/892), a prominent Imami scholar, sought to document and consolidate the doctrine of the Twelfth Imam through his work Akhbār al-Qāʾim. Although the original text has not survived, a substantial portion of its transmitted reports has been preserved in al-Kāfī. Employing a historical-theological approach and drawing upon the traditions attributed to ʿAllān al-Kulaynī in al-Kāfī, this study reconstructs the principal components of his theory of Imamate. The findings indicate that ʿAllān emphasized such foundational principles as the necessity of the continuous existence of the divine proof (ḥujja), the designation of the Imam through explicit textual appointment (naṣṣ), the restriction of the Imamate of two brothers to al-Ḥasan and al-Ḥusayn (a), the transmission of the Imamate from father to son, the legitimacy of a child Imam, the living existence of the Twelfth Imam, and his occultation as a divinely ordained doctrine. The extensive transmission of reports concerning the birth, eyewitness accounts, occultation, and designation of Imam al-Ḥujja (a) in his works demonstrates a deliberate effort to address the theological challenges of his time and to defend the Twelver doctrine of Imamate during one of the most critical periods in the history of Shiʿism.