Short answers, pulled from the story.
About 45,000 years ago a Cro-Magnon population arrived in Europe as Mesolithic hunter-gatherers. These people formed the first distinct lineage of modern English ancestry.
The Anglo-Saxons were the first people to be called English. They began migrating to eastern and southern Britain from southern Denmark and northern Germany in the 5th century AD.
The nation of England was formed on the 12th of July 927 by Aethelstan of Wessex. This occurred after the Treaty of Eamont Bridge following the unification of Anglo-Saxon kingdoms against Danish Viking invasions.
Substantial populations descended from English colonists exist in the United States Canada Australia South Africa and New Zealand. In the 2020 United States census English Americans were the largest group with 46.5 million self-identifying as having some English origins.
A law called Presentment of Englishry required a hundred to prove an unidentified murdered body was that of an Englishman rather than a Norman if they wanted to avoid a fine. This law was abolished in 1340.