Which historic city first became the capital of a kingdom under the Tomara Rajputs in early medieval North India?

Introduction / Context:
Several important cities in India have served as capitals for different kingdoms at different times. Delhi in particular has had a long history as a political centre. The Tomara Rajputs were among the early dynasties to rule from the Delhi region before the coming of the Delhi Sultanate. This question asks which city first became the capital of a kingdom under the Tomaras, thereby testing knowledge about the early political history of Delhi.

Given Data / Assumptions:
We are told that we must identify the city that first became the capital under the Tomara Rajputs. The options list Delhi, Pataliputra, Calcutta, Taxila, and Kannauj, all of which are well known historical cities. We assume that the learner knows that the Tomaras were a regional dynasty in North India associated with the Delhi region and not with eastern or far northern cities like Pataliputra or Taxila.

Concept / Approach:
According to historical tradition, the Tomara Rajputs founded or developed the city known as Dhillika or Dhillika Puri, which later evolved into Delhi. They made this city their capital and controlled the surrounding region before it passed to the Chauhans and then to the early Turkish rulers. The other cities listed in the options were capitals at different times for different kingdoms, such as Pataliputra for the Mauryas and Guptas and Kannauj for later north Indian dynasties, but not for the Tomaras. Therefore, Delhi is the only choice that fits the description in the question.

Step-by-Step Solution:
Step 1: Recall that the Tomara Rajputs ruled in the region around present day Delhi before the rise of the Chauhans and the Delhi Sultanate. Step 2: Remember that they developed Dhillika or early Delhi as their capital. Step 3: Check each option. Pataliputra was an ancient capital in eastern India, not the Tomara centre. Calcutta is a modern colonial city. Taxila belongs to ancient Gandhara. Step 4: Consider Kannauj, which was a capital of other north Indian dynasties but not primarily of the Tomaras. Step 5: Conclude that the city that first became capital under the Tomara Rajputs was Delhi.

Verification / Alternative check:
Historical summaries of the early history of Delhi generally begin with the Tomara Rajputs, followed by the Chauhans. They describe how the Tomaras established their control over Delhi and built fortifications and temples there. This is repeated in many exam oriented books that specifically state Delhi first became a capital under the Tomara Rajputs. No comparable statement is found linking the Tomaras with Pataliputra, Calcutta, Taxila, or Kannauj, which verifies the answer.

Why Other Options Are Wrong:
Pataliputra is wrong because it was a major capital for the Maurya and Gupta empires in eastern India, far from the Tomara base. Calcutta is incorrect since it rose to prominence only under British rule in the eighteenth and nineteenth centuries. Taxila is associated with ancient Gandhara, not with the Tomaras. Kannauj was a centre for Harsha and later Rajput rulers but not the earliest capital of the Tomara Rajputs.

Common Pitfalls:
Some students overthink the question and consider Kannauj because of its medieval importance, even though the Tomaras did not rule from there. Others may misinterpret the phrase first became the capital and forget that the question is specifically about the Tomara dynasty. The simple way to avoid this is to remember a clear association: Tomara Rajputs and early Delhi, which gradually became the famous capital city in later periods as well.

Final Answer:
The city that first became the capital of a kingdom under the Tomara Rajputs was Delhi.