The Jama Masjid of Delhi, one of the largest congregational mosques in India, was constructed during the reign of Shah Jahan in which century?

Introduction / Context:
This question focuses on a major Mughal architectural monument, the Jama Masjid of Delhi. Built near the Red Fort, it is one of the largest mosques in India and a key example of Shah Jahan's patronage of grand religious and civic structures. Determining the century in which it was built helps you place it correctly in the timeline of Mughal architecture, alongside other famous monuments like the Taj Mahal and the Red Fort.

Given Data / Assumptions:

• The monument in question is the Jama Masjid of Delhi.
• It was commissioned during the reign of Shah Jahan.
• The question asks in which century it was built.
• Options range from the fifteenth to the nineteenth century.
• We assume knowledge of when Shah Jahan ruled.

Concept / Approach:
Shah Jahan, the fifth Mughal emperor, ruled in the seventeenth century. He is renowned for building the Taj Mahal in the 1630s and for developing Shahjahanabad, his new capital in Delhi, which included the Red Fort and Jama Masjid. Therefore, any building project unambiguously associated with Shah Jahan, like the Jama Masjid, must also fall in the seventeenth century. The fifteenth and sixteenth centuries belong to earlier sultanates and Akbar's early Mughal phase; the eighteenth and nineteenth centuries come after the great age of monumental Mughal architecture had passed. Thus, the correct century is the seventeenth.

Step-by-Step Solution:
Step 1: Recall that Shah Jahan's reign ran roughly from 1628 to 1658. Step 2: Recognise that his rule falls entirely within the seventeenth century. Step 3: Note that Jama Masjid, like the Red Fort, was built as part of the development of Shahjahanabad, his seventeenth century capital city. Step 4: Eliminate the fifteenth and sixteenth centuries as too early and the eighteenth and nineteenth as too late. Step 5: Select the seventeenth century from the options.

Verification / Alternative check:
You can verify this by aligning major Mughal rulers with centuries: Akbar's great constructions like Fatehpur Sikri and parts of Agra Fort belong to the late sixteenth century; Shah Jahan's projects like the Taj Mahal, Red Fort and Jama Masjid are clearly dated to the seventeenth century. Later rulers such as Aurangzeb focused less on massive architectural projects. Standard architectural histories of Delhi also date the Jama Masjid to the mid seventeenth century. These cross checks confirm that the seventeenth century is the correct answer.

Why Other Options Are Wrong:
15th century: Associated more with late Delhi Sultanate architecture; the Mughal Empire, especially Shah Jahan, had not yet emerged.

16th century: This century covers the reigns of Babur, Humayun and most of Akbar, whose major constructions differ from Shah Jahan's seventeenth century projects.
18th century: By this time the Mughal Empire was in decline, and Jama Masjid was already complete; no major new mosques of this scale were built in Delhi in this period.
19th century: Associated with British colonial urban changes, not with the classical Mughal imperial mosque complexes.

Common Pitfalls:
A common mistake is to vaguely remember that Mughals were active from the sixteenth to eighteenth centuries and then guess any one of those centuries without considering who ruled when. Others confuse Jama Masjid with earlier Delhi mosques built under the sultans. To avoid errors, fix a simple association in memory: Shah Jahan equals seventeenth century, Taj Mahal, Red Fort and Jama Masjid. If you always connect Shah Jahan's name with the seventeenth century, questions about his monuments become straightforward.

Final Answer:
The Jama Masjid of Delhi was built in the 17th century during Shah Jahan's reign.