Within the Red Fort complex at Delhi, the white marble Moti Masjid (Pearl Mosque) was constructed by which Mughal ruler?

Introduction / Context:
The Red Fort in Delhi is a UNESCO World Heritage site and a major symbol of Mughal architectural achievement. Inside the fort stand several important buildings, including the elegant Moti Masjid or Pearl Mosque, made of white marble. Different Mughal emperors contributed various structures to the Red Fort complex, so exam questions often ask you to match a specific building with the emperor who built it. Identifying the patron of the Moti Masjid helps clarify the chronology of Mughal architecture.

Given Data / Assumptions:

• The structure in question is the Moti Masjid inside the Red Fort at Delhi.
• The options list Humayun, Aurangzeb, Akbar and Jahangir.
• We assume basic awareness that these are major Mughal emperors spanning several generations.
• The question asks specifically which ruler constructed this mosque.

Concept / Approach:
There are more than one “Moti Masjid” in Mughal architecture; for example, there is a Moti Masjid in the Agra Fort associated with Shah Jahan. However, the Moti Masjid inside the Red Fort in Delhi is credited to Aurangzeb. He built this private mosque for his personal use and for the royal household. Akbar and Jahangir belong to an earlier phase of Mughal architecture, and Humayun ruled before the Red Fort at Delhi even existed in its later form. Therefore, among the given options, Aurangzeb is the correct answer.

Step-by-Step Solution:
Step 1: Distinguish between different Moti Masjids: one at Agra Fort (Shah Jahan) and one at the Red Fort in Delhi (Aurangzeb). Step 2: Focus on the question, which clearly mentions Moti Masjid within the Red Fort complex at Delhi. Step 3: Recall that Aurangzeb added several religious and defensive structures during his reign, including this mosque. Step 4: Note that Akbar's and Jahangir's architectural works are associated more with earlier forts and palaces, not this specific mosque in the Red Fort. Step 5: Understand that Humayun reigned before the main phase of Red Fort constructions in Delhi. Step 6: Conclude that Aurangzeb built the Moti Masjid at the Red Fort.

Verification / Alternative check:
Architectural history sources and standard history textbooks explicitly state that Aurangzeb built the Moti Masjid in the Red Fort as his private mosque. They also clarify that Shah Jahan, not Aurangzeb, was the great builder of the Red Fort itself and of the Moti Masjid in Agra Fort. This division of credit helps confirm that whenever the question refers specifically to the Red Fort at Delhi, the builder of the Moti Masjid is Aurangzeb.

Why Other Options Are Wrong:

• Humayun: He ruled before the construction of the Red Fort at Delhi in its later Mughal form, so he could not have built this mosque.
• Akbar: Known for the Agra Fort, Fatehpur Sikri and other projects, but not for the Moti Masjid at the Red Fort.
• Jahangir: His reign saw artistic refinement rather than major new fort complexes like this mosque in Delhi.

Common Pitfalls:
A common error is to confuse the two different Moti Masjids and assign both to the same emperor. Some students also mistakenly choose Shah Jahan, even when he is not in the options, because he built the Taj Mahal and many marble structures. To avoid confusion, remember a simple rule: Moti Masjid at Agra Fort belongs to Shah Jahan, whereas Moti Masjid inside the Red Fort at Delhi belongs to Aurangzeb.

Final Answer:
The white marble Moti Masjid in the Red Fort at Delhi was constructed by Aurangzeb.