Robert Harris, Catherine Mayer, Hedd Wyn tribute and Sŵn Festival collaboration join September literary line-up More big names from the book world have been announced to join the line-up for next month’s (Fri 22nd -Sun 24th September) Cardiff Book Festival. Over 30 events taking in best sellers and local talent from the worlds of fiction, non-fiction, prose and poetry were launched back in June- and now organisers have added Cicero Trilogy star Robert Harris, Women’s Equality Party founder Catherine Mayer,…