Four years ago: These ghostly scenes of Lancaster's empty streets as first Covid lockdown hit now seem a world away

At 8.30pm on March 23 2020, then-Prime Minister Boris Johnson told the country that people must stay at home and certain businesses must close.

The stay-at-home order was effective immediately, though only legally effective from 1pm on March 26.

UK residents were told to reduce day-to-day contact with other people, to help reduce the spread of the infection.

This meant:

*Requiring people to stay at home, except for very limited purposes

*Closing certain businesses and venues

*Stopping all gatherings of more than two people in public

Every person in the UK had to comply with these new measures, with relevant authorities, including the police, given the powers to enforce them – including through fines and dispersing gatherings.

As these pictures show, Lancaster suddenly became a ghost town, with the majority of people choosing to remain indoors.

The stay-at-home order was reviewed every three weeks, with NHS bodies strongly advising that those at the highest risk of severe complications from Covid-19 follow special shielding measures, including not leaving their home at all, even for essential reasons, and keeping two metres apart from other household members.

On May 11 2020, following the initial lockdown announcement, the UK-wide rules fractured and separate rules were announced at various times by the four UK governments.