Teodoro A. Agoncillo was a renowned Filipino historian, writer, and educator. Born on November 9, 1922, in Tacloban, Leyte, Philippines, Agoncillo spent his early years studying at the University of the Philippines, where he earned his Bachelor's degree in History. He later pursued his graduate studies at the University of California, Berkeley, and Harvard University.

The book was written during a period of significant social and cultural change in the Philippines. The country was transitioning from a colonial to a post-colonial society, and there was a growing recognition of the need to reclaim and reassert Filipino identity, culture, and history. Agoncillo's work was instrumental in shaping this narrative and providing a framework for understanding the complexities of Philippine history.

The final part of the book covers the post-war period, including the country's struggle for independence and the challenges of nation-building in the aftermath of World War II.

The second part of the book covers the Spanish colonial period, which lasted from the 16th to the 19th century. Agoncillo examines the impact of Spanish colonization on Philippine society, including the introduction of Christianity, the encomienda system, and the exploitation of native resources. He also discusses the emergence of Filipino nationalism and the struggles of the Filipino people against Spanish colonial rule.