Shrove Tuesday is the day before Ash Wednesday, the beginning of Lent and the start of some form of fasting in many religions. It is named for the Christian custom of seeking absolution for sins, or being shriven, before the start of Lent.

Also known as Mardi Gras or Pancake Day, this feasting day traditionally helped use up rich foodstuffs such as eggs, milk, and sugar, before the fasting season began.

"It was said that the world turned upside down on this day, and inferiors were openly allowed to mock their superiors, albeit masked, in rituals of subversion," writes Ken Abala in Food and Faith in Christian Culture.

"Thus there were mock weddings, mock trials, and the lowest person might be crowned king for the day. Rather than pose a threat to the structure of society, it has been suggested that this one day of ritual subversion actually strengthened the social order as a sort of safety valve - allowing people to blow off steam and then return to their stations the rest of the year."