Complex sentence: During this peace, which was to last until 1625, the king worked further in reforming Sweden's military establishment, among which a regular army of 80,000 was settled upon, in addition to an equally great force for the National Guard.
Split into simpler sentences: During this Peace, which was to last until 1625, the King worked further in reforming Sweden's military establishment. Among which, a regular army of 80,000 was settled upon, in addition to an equally great force for the National Guard.