Complex sentence: From 1823 to 1825 Ebert was librarian to the duke of Brunswick at Wolfenbüttel, but returning to Dresden was made, in 1827, chief librarian of the Dresden Royal library.
Split into simpler sentences: From 1823 to 1825, Ebert was librarian to the Duke of Brunswick at Wolfenbüttel. He returned to Dresden in 1827 and was made chief librarian of the Dresden Royal library.