Line of Duty holds its status as the defining TV crime drama of today. The conspiracy theme of the series chimes at a time when public institutions and representatives are distrusted.

Ted Hastings, the show's head of anti-corruption, has emerged as the beating heart of the series. This book reveals how the compelling drama reflects real crimes, events and figures, most notably that of Robert Mark and his battle against Met corruption.

'None of my people would plant evidence. They know I would throw the book at them... followed by the bookshelf'

Starting with a bang - 'I'll put you all back in uniform' were his first words to his team. New Met Commissioner Robert Mark - the inspiration for Ted Hastings - took on his entire corruption-riddled detective branch in his first brutal speech. The scale of the problem facing Robert Mark was institutionalised corruption in CID.

During his four years eleven months as commissioner, he saw 478 men leave the force following or in anticipation of criminal/disciplinary proceedings. Departures in the previous decade had averaged about 16 a year.

Mark's extraordinary career established the need for a dedicated team to investigate corruption that lives on today.