Background:
The Sultanates of the Deccan were a group of five Islamic kingdoms that emerged in the Deccan region of southern India in the 15th and 16th centuries. These Sultanates included the Bahmani Sultanate, the Bijapur Sultanate, the Ahmednagar Sultanate, the Bidar Sultanate, and the Golconda Sultanate. The Vijayanagara Empire, on the other hand, was a Hindu kingdom that ruled over parts of southern India from the 14th to the 17th century. The battle of Talikota was a significant event in the history of the Deccan region.

The Battle of Talikota:
The battle of Talikota took place on January 26, 1565, near the town of Talikota in present-day Karnataka. It was fought between the combined forces of the Sultanates of the Deccan and the Vijayanagara Empire. The Sultanates formed a unified front against the Vijayanagara Empire, which was seen as a major power in the region.

The King of Vijayanagara:
The king of Vijayanagara at the time of the battle of Talikota was Rama Raya. Rama Raya was a powerful and influential ruler who belonged to the Aravidu dynasty. He ascended to the throne in 1542 and was known for his military prowess and administrative abilities. Rama Raya was also known for his diplomatic skills and had established alliances with various local rulers and foreign powers.

Reasons for the Defeat:
There were several reasons for the crushing defeat inflicted on the ruler of Vijayanagara in the battle of Talikota:

1. Lack of Unity: The Sultanates of the Deccan had formed a unified front against Vijayanagara, while the latter lacked a strong and united alliance. Rama Raya's alliances were not strong enough to withstand the combined forces of the Sultanates.

2. Betrayal: Rama Raya's alliances with various local rulers proved to be his downfall. Some of these rulers, such as the rulers of Bidar and Ahmednagar, switched sides during the battle and joined forces with the Sultanates.

3. Military Strategy: The Sultanates had a well-coordinated military strategy, while Vijayanagara's forces were disorganized and lacked proper leadership. The Sultanates also had superior cavalry and artillery, which gave them an advantage on the battlefield.

4. Surprise Attack: The Sultanates launched a surprise attack on Vijayanagara's forces, catching them off guard. This further contributed to the defeat of the Vijayanagara Empire.

Aftermath:
The defeat at the battle of Talikota was a major blow to the Vijayanagara Empire. The city of Vijayanagara was looted and destroyed by the victorious Sultanates, marking the decline of the empire. Rama Raya was captured and executed by the Sultanates. The defeat also led to a power vacuum in the region, with the Sultanates vying for control over the Deccan.

Overall, the battle of Talikota was a turning point in the history of the Deccan region. It marked the end of the Vijayanagara Empire's dominance and the rise of the Sultanates of the Deccan as the new powers in southern India.