Engaging, humane, sharp, funny and unforgettable, Alan Bennett opens this year's Festival with Keeping On Keeping On, his inimitable record of life from his peerless 2005 to 2015 diaries. In the footsteps of the phenomenally successful Writing Home and Untold Stories, this is a decade that saw four premieres at the National Theatre and films of The History Boys and The Lady in the Van, read aloud as only Bennett can.