Complex sentence: Johnson began acting at the age of six, Staring in, The thief lord as Prosper performing as the son of Macduff alongside Rufus Sewell playing the lead role in Macbeth in 1999, and in Arthur Miller's "All My Sons" in 2000.
Split into simpler sentences: Johnson began acting at the age of six, Staring in, The thief lord, as Prosper. Performing as the son of Macduff alongside Rufus Sewell playing the lead role in Macbeth in 1999, and in Arthur Miller's "All My Sons" in 2000.