Why did Vasco da Gama fail to make a trade treaty at Calicut?

Vasco da Gama failed to secure a trade treaty during his first arrival in Calicut in 1498 due to a combination of diplomatic and cultural factors.1

His efforts were undermined by the following issues:

• Inadequate Offerings: Da Gama brought gifts and trade goods that were considered "trumpery" and cheap. While these items may have been suitable for trade in West Africa, they were not in demand in the sophisticated markets of India.1
• Hostility from Local Merchants: The established Muslim Arab merchants in Calicut viewed the Portuguese arrival as a threat to their commercial interests and actively opposed the formation of a treaty.1
• Poor Diplomacy: Da Gama’s behavior was perceived as rude, which, coupled with his insignificant gifts, alienated the Zamorin, the Hindu ruler of Calicut.1
• Misconceptions: The Portuguese expedition arrived with the mistaken belief that the Hindus were Christians, leading to a fundamental misunderstanding of the local political and religious landscape.1

These failures, compounded by da Gama's lack of local knowledge, ultimately led to his departure without achieving his primary objective of establishing a formal trade agreement.1