Original: It came into being on May 1st , 1707 , with the merger of the Kingdom of Scotland and the Kingdom of England , as agreed in the 1706 Treaty of Union and ratified by the Acts of Union 1707 , to create a single kingdom encompassing the whole of the island of Great Britain and its minor outlying islands , excluding Irelandâ '' which remained a separate jurisdiction under the British crown .
Simplified: It was created by the merger of the Kingdom of Scotland and the Kingdom of England , under the Acts of Union 1707 , to create a single kingdom that included the whole of the island of Great Britain .