Timewatch focused on an environmental disaster of 1783 which killed thousands of Britons. Victims of a huge volcanic eruption in Iceland, they choked on the poisonous gases that enveloped Europe.
The ensuing winter was one of the worst on record, and took countless more lives.
The tragedy wrought by the Laki eruption is well documented in Iceland but its impact on Britain has remained a mystery for the past 200 years. Timewatch went in search of the evidence of Britain's forgotten disaster.
Here, viewers share their thoughts on the programme.