In the main line of succession of the Mughal empire, Shah Jahan was the ______ Mughal ruler.

Introduction / Context:
Knowing the correct order of Mughal emperors is a fundamental part of Indian medieval history. Questions that ask whether a ruler was the third, fourth, or fifth in line test chronological understanding and help students remember how the empire evolved. Shah Jahan is famous for his architectural patronage, including the Taj Mahal, but answering this question correctly means placing him correctly within the sequence of Mughal emperors from Babar onwards.

Given Data / Assumptions:

• The question refers to the main line of Mughal emperors ruling over most of North India.
• We start counting from Babar, the founder of the Mughal empire in India.
• The options are Fourth, Third, Sixth, and Fifth.
• We assume the standard sequence: Babar, Humayun, Akbar, Jahangir, Shah Jahan, Aurangzeb.

Concept / Approach:
The approach is to list the emperors in chronological order and count. Babar founded the empire after the First Battle of Panipat (1526). His son Humayun succeeded him. After a period of struggle and brief exile, Humayun was succeeded by Akbar, under whom the empire greatly expanded. Jahangir followed Akbar, and Shah Jahan came after Jahangir. Therefore Shah Jahan is the fifth emperor in this main succession line. Aurangzeb comes later as the sixth major Mughal emperor in this widely accepted sequence.

Step-by-Step Solution:
Step 1: List the emperors in order: Babar (1), Humayun (2), Akbar (3), Jahangir (4), Shah Jahan (5), Aurangzeb (6). Step 2: Identify the position of Shah Jahan in this list. Step 3: Observe that Shah Jahan comes after Jahangir and before Aurangzeb. Step 4: Count his position: he is the fifth in this standard order. Step 5: Choose Fifth from the options provided.

Verification / Alternative check:
You can also verify by associating each emperor with a key event: Babar with Panipat, Humayun with his temporary loss of the throne, Akbar with the consolidation of the empire, Jahangir with relative stability and cultural developments, and Shah Jahan with monumental architecture like the Taj Mahal and Red Fort in Delhi. Since these events clearly place Shah Jahan after four earlier emperors, this confirms he was the fifth.

Why Other Options Are Wrong:
Third: This would wrongly place Shah Jahan immediately after Akbar, ignoring Jahangir.
Fourth: This position actually belongs to Jahangir, not Shah Jahan.
Sixth: This corresponds to Aurangzeb in the main sequence, not Shah Jahan.

Common Pitfalls:
A common error is to forget Jahangir's reign and jump directly from Akbar to Shah Jahan when listing emperors. Another mistake is to confuse the total number of prominent Mughal rulers with Shah Jahan's exact place in the succession. Building a simple timeline with emperor names and key dates can prevent these errors.

Final Answer:
Shah Jahan was the fifth Mughal ruler in the main line of succession.