Historical Linguistics is the study of how languages change over time. It examines the evolution of languages, their relationships, and the processes that lead to linguistic change. By analyzing historical texts and comparing languages, linguists can reconstruct ancient languages and understand how modern languages have developed. This field also explores the reasons behind language change, such as social, cultural, and environmental factors. Through methods like comparative reconstruction and internal reconstruction, researchers can trace the lineage of languages and uncover the history of human communication.