The Tomara Rajputs were defeated in the middle of the twelfth century by the Chauhans of which important Rajput centre.

Introduction / Context:
This question relates to the early medieval period in North Indian history, when several Rajput clans competed for power. The Tomaras and the Chauhans were two such important clans. The Tomaras ruled in and around Delhi, while the Chauhans, also known as Chahamanas, were centred on Ajmer. The question asks which Rajput centre is linked with the Chauhans who defeated the Tomaras in the mid twelfth century. This tests awareness of the political geography of Rajput states before the Turkish invasions.

Given Data / Assumptions:

• The Tomara Rajputs are mentioned as one side in the conflict. • They were defeated in the middle of the twelfth century. • The victors were the Chauhans. • The question asks for the region or centre associated with the Chauhans.

Concept / Approach:
The Chauhans are historically associated with Ajmer and later Delhi under Prithviraj Chauhan. Ajmer was their original stronghold in present day Rajasthan. From there they expanded into other regions, including taking control of Delhi from the Tomaras. Therefore, to answer the question, we simply need to recall that Ajmer, not Ayodhya, Dwarka, or Gwalior, was the principal centre of the Chauhans who defeated the Tomaras.

Step-by-Step Solution:
Step 1: Recall that the Tomara clan ruled in and around Delhi before the rise of the Chauhans. Step 2: Remember that the Chauhans, or Chahamanas, had their early capital at Ajmer in Rajasthan. Step 3: In the mid twelfth century, the Chauhans of Ajmer, under rulers like Vigraharaja and later Prithviraj Chauhan, extended their power to Delhi. Step 4: This expansion resulted in the defeat of the Tomaras by the Chauhans of Ajmer. Step 5: Among the given options, Ajmer is therefore the correct answer.

Verification / Alternative check:
Historical accounts in textbooks show that Ajmer and Delhi formed the core of the Chauhan territories before the Ghurid invasions. Many inscriptions and literary works refer to the Chauhans as lords of Ajmer. Ayodhya, Dwarka, and Gwalior are important historical cities but are associated with other dynasties and stories. Kannauj was contested between Palas, Pratiharas, and Rashtrakutas, not the primary base of the Chauhans in this context. This confirms that Ajmer is the correct centre linked with the Chauhans who defeated the Tomaras.

Why Other Options Are Wrong:
Ayodhya: Famous as a religious city associated with Lord Rama, but not the main political centre of the Chauhans. Dwarka: A coastal city in Gujarat associated with Krishna legends, not with the Rajput Chauhans of North India. Gwalior: A historical fortress city that saw many rulers, but it was not the base of the Chauhans who defeated the Tomaras. Kannauj: Important in early medieval politics but associated mainly with the Pratihara dynasty and later other powers, not the Chauhans who displaced the Tomaras from Delhi.

Common Pitfalls:
Students sometimes confuse different Rajput clans and their centres because there were many small states. They may also choose a well known city like Kannauj even when it is not directly linked with the dynasty in the question. To avoid this, it is useful to remember a few simple pairs: Chauhans with Ajmer, Solankis with Anhilwara Patan, and Gahadavalas with Kannauj. Associating each dynasty with its chief town makes such questions much easier.

Final Answer:
The Tomara Rajputs were defeated in the mid twelfth century by the Chauhans of Ajmer.