Simplify the following text for a Grade 10 native English-speaking person.
Original: In 14 CE , just after Augustus ' death and the accession of his heir and stepson Tiberius , a massive raid was conducted by the new emperor 's nephew Germanicus .
Simplified: In 14 AD , just after Augustus ' death , and the accession of his heir and stepson Tiberius , a huge raid was led by the new emperor 's nephew Germanicus .