Complex sentence: Green (1850) p.345 The king soon discovered his daughter's intentions, but not yet aware that she had already committed to them, he seized Joan's lands and continued to arrange her marriage to Amadeus of Savoy.
Split into simpler sentences: Green (1850) p.345 The king soon discovered his daughter's intentions but did not yet realize she had already committed to them. Upon finding out, he took all of Joan's lands and continued to arrange the marriage of Joan and Amadeus of Savoy.