In the early 17th century, the Kaicho embassy set sail from Japan in 1613, marking a significant moment in Japan-Spain relations. This mission, supported by Date Masamune and sanctioned by Shogun Tokugawa Ieyasu, aimed to secure trade and religious privileges with Spain and the Pope. The embassy faced numerous challenges, beginning with a tumultuous two-month journey across the Pacific Ocean.
Upon reaching New Spain (modern-day Mexico), the mission sought a diplomatic audience with King Philip III, eventually holding a formal meeting in Madrid. However, unknown to the travelers, relations had soured due to Spain's existing trade monopoly in the Pacific and internal conflicts within the embassy itself.
Focusing on religion, Sautello, a Franciscan friar accompanying the embassy, attempted to promote Catholicism among the Japanese, with some members being baptized in Mexico City. Yet, the embassy's religious and trade objectives largely went unmet due to rising Christian persecution in Japan and Philip III's reluctance.
The embassy's notable achievements included Hasakura Tsunenaga's baptism and citizenship in Rome, symbolizing an intercultural exchange rather than concrete diplomatic success. Despite challenges, the mission illustrated the broader geopolitical dynamics and cultural encounters of the era.