July 19 is Flitch Day, a holiday that took place in the 12th century English village of Dunmore Piory. According to history, a flitch of bacon (half a pig) was given to any married couple who could prove to a jury that they had lived together in harmony and fidelity the entire previous year.
By the middle of the 14th century, the poem of Piers Ploughman mentioned the custom in a manner that implies a general knowledge of it among his readers. Chaucer also refers to it.
Victorian novelist Harrison Ainsworth revived the Fitch Trials as an entirely civic event. In 1855, he published the popular novel The Custom of Dunmow, which recounts the attempts of Jonas Jones to win the Flitch by marrying a succession of wives hoping to find the perfect one. The Trials were once again staged in Great Dunmow.
Since then, the trials have been held regularly and since the end of WWII, every 4 years in a leap year. The next Flitch Trials will be July 19, 2020.
In researching this post, I read that the custom of awarding a Flitch to those who can prove marital harmony is not unique to Dunmow, but I could find no other references.
It is not a competition between the couples. All the couples could be successful in their claim. To see the 2016 winners, visit the Official Website.