This article explores historical reasoning, an important activity in history learning. Based upon an extensive review of empirical literature on students' thinking and reasoning about history, a theoretical framework of historical reasoning is proposed. The framework consists of six components: asking historical questions, using sources, contextualization, argumentation, using substantive concepts, and using meta-concepts. Each component is discussed and illustrated by examples from our own research. The article concludes with suggestions on how to use the framework both in future research and in educational practice.