The first king of a unified England was King Æthelstan, who reigned from 924 to 939 AD. He is often regarded as the first true king of England because he successfully consolidated various Anglo-Saxon kingdoms, including Mercia and Wessex, into a single entity. Æthelstan implemented a series of military and political strategies that solidified his power, expanding his influence over the British Isles. His reign is marked by efforts to create a sense of national identity, promote Christianity, and foster trade and diplomacy. Æthelstan’s legacy is foundational, as he set a precedent for subsequent English monarchs and the development of the English state.