More properly, this refers to a rare alliance between Essex and Kent 640 years ago, in 1381. That year saw the Peasants' Revolt, or Wat Tyler's Rebellion.

To understand the background, we have to go back to a catastrophic pandemic – the Black Death of 1348-1350, which saw the death of at least 30% and possibly as much as 45% of the population.

For the survivors, the aftermath involved opportunities as well as grief. Suddenly there was a shortage of labour, and peasants who had been tied to the land and their feudal lords under the system of serfdom began to push against their bonds and even move to seek better conditions and wages elsewhere. Similarly, skilled craftsmen and merchants looked for better lives in the post-pandemic world.

Against this, the government was creating fresh pressures with the Hundred Years' War with France, funded by an unpopular Poll Tax.

A radical priest called John Ball sprang up and started to sow dissent among the peasants. Ball, who some think was born in Peldon near Colchester, came up with the famous phrase, 'When Adam delved [dug] and Eve span, who was then the gentleman.' Essentially, he was saying that all were born equal, an idea that was almost unthinkable then, and even until the 19th Century.

One of those inspired by Ball was Wat Tyler, who became the chief leader of the revolt. Although claimed by Essex, it's possible he was born in Kent. What we do know, however, is that the rebellion was finally sparked by an attempt to collect unpaid Poll tax in Brentwood, led by a royal official called Bampton. He summoned villagers from Corringham, Fobbing and Stanford-le-Hope to explain the non-payment, and they turned up with weapons. Bampton fled, but several of his clerks were killed.

The rebellion rapidly spread across Essex, Kent, Suffolk and Norfolk. Wat Tyler led the Kentish forces to Blackheath, where royal representatives tried to negotiate. Rebels from Essex, Suffolk and Norfolk advanced via Chelmsford. The 14-year-old Kind Richard II sought safety in the Tower of London, and the rebels entered the city, and joined by London citizens began to sack key centres of power, including the Savoy Palace, the Temple (the centre for English law) and even the Tower of London, where the Bishop of London the Lord High Treasurer were killed.

The desperate Richard II made a series of promises to secure a truce, including the abolition of serfdom. At a meeting with the rebels at Smithfield on 15 June, Richard escort killed Tyler. Richard soothed the situation long enough to make his escape, and the Mayor of London used the time to assemble a strong militia which dispersed the rebels.

Ignoring his promises, the king now took the offensive, and powerful royal forces ranged across Kent and East Anglia, killing at least 1,500 rebels. The last were defeated in a battle at North Walsham, Norfolk. The more prominent leaders were executed by hanging, drawing and quartering as a lesson to other would-be rebels.

However, the ideals of the rebellion live on in modern democracy, though when it falls short in the public eye, Wat Tyler's name is still invoked – for example, in the Poll Tax riots during Margaret Thatcher's administration.