Harsha’s military expansion in the Deccan was checked by Pulkesin II. When Pulkesin II pushed forth up to the Narmada, he came face to face with Harshavardhana of Kanauj who already had the title Uttarapatha Ishvara (Lord of the north). In a decisive battle fought on the banks of the river Narmada, Harsha lost a major part of his elephant force and had to retreat. The Aihole inscription describes how the mighty Harsha lost his harsha (joy) when he suffered the ignominy of defeat.

Harsha's military expansion in the Deccan was checked by Pulakesin II.

Explanation:
1. Harsha was a prominent ruler of the Indian subcontinent who reigned over the northern regions from 606 to 647 CE. He was known for his military conquests and attempts to unify different parts of India under his rule.
2. Harsha's military expansion in the Deccan, the southern part of India, faced significant resistance from Pulakesin II, who was the ruler of the Chalukya dynasty.
3. Pulakesin II was a powerful and skilled ruler who successfully defended his kingdom against Harsha's attempts to expand his empire into the Deccan.
4. The Chalukya dynasty was based in the present-day Karnataka region and had a strong military and administrative structure. Pulakesin II was known for his military strategies and was able to repel Harsha's forces.
5. Pulakesin II's resistance to Harsha's expansion can be seen as a significant event in Indian history as it prevented the consolidation of Harsha's empire in the Deccan region.
6. The conflict between Harsha and Pulakesin II is often seen as a clash between two powerful rulers who sought to expand their influence and control over different parts of India.
7. Despite his unsuccessful attempts to conquer the Deccan, Harsha was able to establish diplomatic relations with Pulakesin II and other southern rulers, which helped in maintaining peace and stability in the region.
8. Harsha's military expansion was checked by Pulakesin II's strong defense and strategic abilities, highlighting the decentralized nature of power in ancient India, where regional kingdoms had their own military strength and political autonomy.