Simplify the following text for a Grade 15 native English-speaking person.
Original: de facto deposed by various occupations in the Great French War , he was a grandson of George II AugustusGeorge III 's son , Regent George agreed to pass Saxe-Lauenburg to his Danish cousin in a general territorial redeployment at the Congress of Vienna
Simplified: de facto deposed by various occupations in the Great French War , he was a grandson of George II AugustusGeorge III 's son , Regent George agreed to pass Saxe-Lauenburg to his Danish cousin in a general reorganisation of land at the Congress of Vienna