This Sunday marks the beginning of Holy Week, the most sacred week in the liturgical year in Christianity.

It begins with Palm Sunday, which commemorates Jesus's entrance into the city of Jerusalem, and concludes with his death on Holy Saturday and his resurrection on Easter Sunday.

Curious as to why Holy Week begins with Palm Sunday? Are you wondering what traditions and meals are enjoyed during the week? Not sure what's so special about palm leaves, anyway? We're happy to fill you in!

Check out the history of Palm Sunday below, as well as its importance as the start of Holy Week.

What's Palm Sunday? Why are palm leaves used?

Palm Sunday dates all the way back to the 4th century, where ceremonies were taking place in Jerusalem. By the Middle Ages, the ceremony had spread across Europe.

It used to be far more elaborate than how it's currently celebrated. The procession began in one church, went to a different church where the palms were blessed, and then returned to the first church to begin the singing of the liturgy. This was then followed by chanting from three deacons of the Passion of Christ, or Matthew 26:36–27:54.

Reformations in the 1950s and 1960s simplified the ceremony, focusing more on the suffering and death of Christ.

For those curious about why palm leaves are used, it ties into Jesus's entrance into Jerusalem. As he rode into the city on a donkey, his followers spread palm branches at his feet and called him "Hossana," or savior. They were seen as symbols of victory or triumph at the time. His entrance into Jerusalem and said festivities are mirrored with the activities at the beginning of Holy Week today.

CT Jobs: As the Connecticut jobs picture brightens, some see hope for young workers. Here's why.

Nowadays, you'll find date palm leaves or, in other cases, twigs from local trees, blessed by churches and given to their congregations. Palms kept by the church are sometimes saved until next year's Ash Wednesday, to be used in that ceremony.

What do Christians eat during the holiday?

While Palm Sunday doesn't usually have a meal or theme in terms of cuisine in the U.S., there's a mix of different, historical meals consumed for the holiday.

Pax cakes, for example. No, not pancakes, pax cakes. During the Middle Ages in England, churches handed out small biscuits, or pax cakes, after Palm Sunday service. The word "Pax" in Latin means "peace," and clergy would sometimes say "God and good neighborhood" as they handed them out. The biscuits would have the image of a lamb and a flag to represent Jesus and peace.

Another culinary tradition involves drinking water mixed with licorice from Spain, dating back in England's history. While the roots of this are unclear, it's been associated with holy wells since the 1700s. Licorices was sort of a natural disinfectant and sweetener. Before the first World War, children would go to a licorice sweetened well and drink a bottle of water while wearing a sprig of a willow tree. The tradition died out after the war.

The month of Ramadan starts April 2: Here's what to know about the Islamic holiday

In Greece, fried salt cod, or "bakaliaros," is the traditional Palm Sunday meal. Lent generally discourages individuals from consuming meat, including fish, but an exception was made on Palm Sunday for cod given its connection to Biblical stories.

Finally, figs have been a cornerstone of many different dishes in years past and present. You can thank Jesus for that as well, who ate from a fig tree when he reached Jerusalem.

This article originally appeared on The Bulletin: Holy Week and Easter: Why it all begins with Palm Sunday