The Roman conquest of modern-day Spain and Portugal was a process that took almost two full centuries due to resistance efforts from groups of pre-Roman Iberians. While possibly hundreds of tribes were already on the Iberian Peninsula when the Romans arrived, this project focuses on Roman interaction with two groups frequently mentioned by ancient Greeks and Romans: the Turdetanians of Andalusia, Spain and the Lusitanians of Portugal and Extremadura, Spain. Utilizing ancient sources, this paper examines what we know about each tribe before Roman presence in Iberia, how they each reacted to Roman control, and finally why the Turdetanians and the Lusitanians reacted differently. I conclude that the distinct Turdetanian and Lusitanian responses to Roman hegemony can be explained by their different cultural, geographic, and economic situations at the time of Roman invasion beginning in the third century B.C.E
