Iran's conservative media love to use the phrase "the old fox" to describe Britain and remind audiences of what they see as the cunning, sly and devious actions of the UK.
The stock phrase cropped up again on the occasion of Foreign Secretary Philip Hammond's visit to Tehran to reopen the British embassy nearly four years after it was closed amid attacks by hardline protesters.
Conservative daily Hemayat carried a front page report headlined "The old fox arrived with its lights turned off". Another conservative daily, Resalat, published a report entitled "No-one is happy with the return of the old fox".
As in many other countries, foxes symbolise a cunning and sly character in Persian literature but where does the term "the old fox" come from?
Anti-British poet
In the Persian language, a poet who died in Tehran around 85 years ago was the first to promote the phrase.
Seyyed Ahmad Adib Pishavari (1844-1930) was an expert in literature and philosophy, whose work was characterised by anti-British sentiment.
Born in Peshawar, in today's Pakistan, he lost many of his relatives during the wars with British forces in 1857-58. Adib later moved to Iran where he continued his education.
There, he experienced major events such as the Constitutional Revolution, in 1905-07. The revolution led to the establishment of the parliament during the Qajar dynasty.
Despite the fact that the majority of people backed the creation of the constitutional monarchy, Adib described the revolution as a "plot" hatched by Britain.
His anti-UK feelings emerged in his poetry, particularly during World War One. In fact, he wrote several poems in support of the German Kaiser.
Throughout his works, he often likened the UK to animals - an "old fox", an "ominous raven" and a "venomous viper" - to attack British colonial policies in Iran and the region, policies which he saw as "evil". The term, the old fox, however, remains popular to this day.
The following is a translation of one of Adib's poems:
Many an ancient house
Was razed after you crept in
You seized lands through your fox games
You have escaped hundred of traps, like an old fox.
Hostile campaign
There's been an orchestrated media campaign against the reopening of the British embassy. Conservative media outlets are highlighting key moments in Iran and Britain's troubled history including Britain's complicity in the CIA 1953 coup which toppled the democratically elected Prime Minister, Mohammad Mossadeq.
They also accuse Britain of helping mastermind and provoke the mass street protests against the re-election of Mahmoud Ahmadinejad, which followed the disputed presidential elections in 2009. Conservatives refer to those protests as "sedition".
"Such documented historical evidence is only one part of the treason and deception of the evil British government against the noble people of Iran. That's a strong reason for the historical hatred by Iranians towards Britain and that's why they call it 'the old fox'," says a commentary from the conservative Mehr news agency.
Some hardline users also took to social media platforms to criticise the perceived thaw in the bilateral relations by posting pictures and cartoons of "the old fox".