Complex sentence: Royle was a journeyman apprenticing under Virginia's "public printer" ("printer to the public") William Hunter and became his foreman in the print shop around 1758 when he was 26 years old.
Split into simpler sentences: Royle was a journeyman who apprenticed under Virginia's "public printer" ("printer to the public") William Hunter. He became the foreman in the print shop around 1758 when he was 26 years old.