After the Black Death in the medieval era, the most notorious plague to hit this country was the Great Plague of 1665/1666. This is most famous for taking 15-25% of London's population, and for being immediately followed in 1666 by the Great Fire of London.

What is less well known is that Colchester had proportionately more deaths, and was the worst-hit town in the country.

This was Bubonic Plague, and the symptoms included fever, sweating, headaches, vomiting and 'buboes' – swollen lymph nodes, hence the name. Some got a pneumonic form of the disease which was even deadlier. It is a bacterial disease, and pre-antibiotics the fatality rate was over 60%.

Transmission (apart from the few who got the pneumonic form) was from infected rodents and fleas.

Although the 1665 Plague did not devastate the population in the way that the Black Death Death did (perhaps 40% died in the latter), it was still terrifying, and familiar measures of shop, pub and theatre closures were followed, along with isolation, restrictions on travel and hurried burials. Unfortunately, if people still lived among the rats and fleas that were transmitting the disease, these measures could have limited value.

The Plague spread to Colchester from London in August 1665, and was recorded by a diarist from Earls Colne, the Reverend Josselin. A lot of his fascinating comments are recorded by Elaine Barker on the Mersea Museum site.

Josselin records its arrival on 13th August, and two weeks later is commenting that 'Colchester seeke [flee] into the country for dwellings' – a common pattern where those able to, fled into rural areas, only to spread the disease further. Colchester had a large population for the time – 10,000, mostly within the old Roman wall circuit, plus a further 2,000 prisoners from the war with Holland.

'Searchers' were appointed to visit houses where people had died, and burials were conducted at night. Josselin records on September 16th that 'Colchester increaseth in illness being spread over the whole town.' People turned to religion, and weekly fasting and prayer was ordered.

Burials were not allowed in regular churchyards unless a separate area could be isolated, so plague pits were established. It is believed that plague pits were established at 'The Mount', outside the town walls and just off the Mersea Road, and at High Woods.

The cold winter of 1665/1666 suppressed the plague in London, and evacuees (including the King and his court) started to return. But Colchester benefited less from this, and it was still rife in the spring of 1666, Josselin saying 'It's at Dedham and several villages, Lord in mercy remove thy hand.'

Summer was even worse, both in Colchester and London, and it was not until November 18th that Josselin ceased referring to it in his diary. The population of Colchester had gone from 10,305 in 1662 to 4,114 in 1666. 4,559 actual plague deaths are recorded, and it's likely that many of the other missing people had not returned from the countryside. 279 houses were empty in March 1666 when local taxes were calculated.