Des is the biggest drama launch on the channel since Cleaning Up in 2019.
The three-part series, featuring David Tennant as serial killer Dennis Nilsen, opened to critical acclaim and is the second biggest drama launch episode across all channels so far in 2020.
The first episode peaked with 5.9m and was watched by almost a third of all viewers [32 per cent] across its slot.
Written by Luke Neal and developed by Luke Neal and Lewis Arnold, Des is based on material from the book Killing for Company by Brian Masters, which focuses on one of the most infamous cases in UK criminal history, that of serial killer Dennis Nilsen.
Nilsen murdered boys and young men in his flat from 1978 to 1983; his crimes going undetected for five years. It was only when DCI Peter Jay was called to Nilsen’s address on 9 February, 1983, to investigate human fragments of flesh and bone clogging the drains, that the police realised they had a serial killer on their hands.
Nilsen was arrested and convicted at the Old Bailey of six counts of murder and two of attempted murder. He was sentenced to life imprisonment, which was replaced by a whole life tariff in 1994. He died in May 2018.
ITV has three of the top five most watched drama launches this year.
As well as Des, the first episodes of Quiz [5.3m] and Van Der Valk [5.2m] are also ranked in the top five by overnight audience.