Before the Acts of Union 1707, the Office of the Admiralty and Marine Affairs administered the Royal Navy of the Kingdom of England, which merged with the Royal Scots Navy and the absorbed the responsibilities of the Lord High Admiral of the Kingdom of Scotland with the unification of the Kingdom of Great Britain. The Admiralty was among the most important departments of the British Government, because of the Royal Navy's role in the expansion and maintenance of the British Empire in the 17th century, in the 18th century, and subsequently.