With the British national anthem playing in the background, Britain’s foreign secretary, Philip Hammond said the opening of the embassy with the formal raising of the UK’s Union flag represented the start of a new phase in relations between the countries.
Britain has operated without an embassy in Tehran since protestors stormed the building four years ago in protest against sanctions.
The two main diplomatic compounds were ransacked and looted. Anti British graffiti remains daubed on the walls.
CCTV’s Richard Bestic filed this report from London.