Among the pre-Mutiny writings of Sayyid Aḥmad Khān (1817–1898), the Indian Muslim reformer, Āsār al-ṣanādīd, a history and description of Delhi, and its principal buildings and monuments, is a most impressive achievement. From the day of its publication onwards it has repeatedly been acknowledged as an important contribution to our knowledge of the history and archaeology of Delhi. However, on the whole, and in spite of recent re-editions of the work, no due attention has been paid to the fact that as early as 1854, i.e. only seven years after the first edition, Sayyid Aḥmad Khān published a second one remarkably different in form and content. We should like, in what follows, to present some evidence that may help to explain why and how this significantly altered second edition came about. This will also contribute to a better knowledge of Sayyid Aḥmad Khān's early intellectual development.