Britain was divided into the states of England, Scotland, and at the beginning Wales, for most of its history since 1200. At this time, the dominance of England was already obvious, however.
For a while, it seemed that Scotland's greatest king Alasdair IV could've turned the tide by building an empire encompassing Scotland, Ireland and Scandinavia as a counterweight to England, but after his empire fell apart, England became predominant in Ireland again. The first English Civil War only delayed the inevitable. After Scotland participated in the anti-French War, it lost its independence in 1694, thus uniting the British Isles for the first time in history under the Staffords. Even later developments wouldn't change this fact.