In the history of the Delhi Sultanate, which ruling dynasty was founded by Khizr Khan as its first Sultan?

Introduction / Context:
Khizr Khan is an important name in the later phase of the Delhi Sultanate. After the decline of the Tughlaq power and the brief rule of Timur's nominee, he established a new ruling house at Delhi. Many competitive examinations test which dynasty he founded, because it helps candidates remember the sequence of the last Delhi Sultanate dynasties before the Mughals appeared on the scene.

Given Data / Assumptions:

- The question asks about the dynasty started by Khizr Khan. - The setting is the Delhi Sultanate after the weakening of the Tughlaqs. - The options mention the Sayyid, Lodi, Rajput and Khalji houses. - We assume standard textbook chronology of Delhi Sultanate dynasties.

Concept / Approach:
The last four main ruling houses of the Delhi Sultanate were the Khalji, Tughlaq, Sayyid and Lodi dynasties, followed later by the Mughal conquest. Khizr Khan was a former governor under the Tughlaqs who, after Timur's invasion, was installed as a ruler in Delhi. He did not take the full title of Sultan but effectively founded a new line that historians call the Sayyid dynasty. The Lodis came later, and Rajputs are a broader group of ruling clans rather than a specific Delhi Sultanate dynasty in this context.

Step-by-Step Solution:
Step 1: Recall the chronological order of dynasties: Slave (Mamluk), Khalji, Tughlaq, Sayyid, and Lodi. Step 2: Note that Khizr Khan emerged after the collapse of effective Tughlaq control and after Timur's raid on Delhi in 1398. Step 3: Understand that Khizr Khan ruled from Delhi and laid the foundations of a new ruling house recognised as the Sayyid dynasty. Step 4: Remember that the Lodi dynasty was founded later by Bahlul Lodi, not by Khizr Khan. Step 5: Match the correct name from the options with this information, which clearly points to the Sayyid dynasty.

Verification / Alternative check:
Standard histories of the Delhi Sultanate list Khizr Khan (reigning from 1414) as the founder of the Sayyid dynasty, which lasted until 1451. Only after the Sayyids did the Afghan Lodi rulers take power. The Khalji dynasty had already ended with the rise of the Tughlaqs much earlier. This cross check of names and dates confirms that Khizr Khan cannot be associated with the Lodi or Khalji dynasties and that the label applied to his line is Sayyid.

Why Other Options Are Wrong:
The Lodi dynasty: Founded later by Bahlul Lodi; it replaced the Sayyids rather than being founded by Khizr Khan.
The Rajput dynasties: Rajputs as a group ruled many regions, but there is no single Rajput dynasty of Delhi founded by Khizr Khan.
The Khalji dynasty: This was an earlier ruling house beginning with Jalal ud din Khalji and Ala ud din Khalji, not linked to Khizr Khan.

Common Pitfalls:
Students sometimes confuse the sequence of the last Delhi Sultanate dynasties, especially Sayyid and Lodi, because both ruled in the fifteenth century. Another common mistake is to associate any new ruler after the Tughlaqs directly with the Lodi dynasty. A simple way to remember is that Khizr Khan equals Sayyid dynasty, and Bahlul Lodi equals Lodi dynasty.

Final Answer:
The dynasty started by Khizr Khan was the Sayyid dynasty.