This document provides an introduction to Leonard Y. Andaya's book "Leaves of the Same Tree: Trade and Ethnicity in the Straits of Melaka". It discusses how trade has long been a dominant theme in Southeast Asian history due to the region's strategic location between major civilizations. The Straits of Melaka in particular served as an important hub for international trade for over 2000 years. The introduction notes that while much has been written about the impact of trade, little attention has been given to its role in ethnic formation. Local communities along the straits increasingly engaged in trade and differentiated themselves from others to take advantage of economic opportunities, contributing to the complexity of ethnicity in the region.