Complex sentence: In the name of Theophanu, Adalberon offered Lothair the recovery of Lotharingia; shortly after, the King of the Franks formally claimed the guardianship of his infant nephew Otto III and the custody of the Lotharingia.
Split into simpler sentences: In the name of Theophanu, Adalberon offered Lothair the recovery of Lotharingia. Shortly after Lothair formally claimed the guardianship of his infant nephew Otto III and the custody of the Lotharingia.