Complex sentence: The older William was nicknamed "Willie" whereas younger William is nicknamed "Bill" were both were named after their grandfather (Joseph's father), who (along his wife Isabelle-Joseph's mother -) was killed during the Tauron Uprising.
Split into simpler sentences: The older William was nicknamed "Willie" whereas the younger William is nicknamed "Bill". Both were named after their grandfather, who along with their grandmother Isabelle was killed during the Tauron Uprising.