In New Orleans and other cities around the world, millions of people dressed up in elaborate costumes, watched parades, listened to music and partied the day away to celebrate Fat Tuesday, a period of revelry before Lent on the calendar for Roman Catholics and other Christians.

Though better known for all of the wild secular celebrations, Mardi Gras and Carnival ultimately give way to a more calm religious period for many Christians known as Ash Wednesday. Ash Wednesday is the start of Lent's some 40 days of fasting and repentance before Easter Sunday.

Ash Wednesday signifies penance and reflection, according to the United States Conference of Catholic Bishops, and also symbolizes Christians’ dependence upon God's mercy and forgiveness.

See an article on Lent and Ash Wednesday on phillyburbs.com

The Ash Wednesday tradition is rooted in Old Testament scripture, in which the king of Nineveh rose from his throne, wrapped himself in sackcloth and sat in ashes to signify repentance.

In Roman Catholic churches, palm branches from the previous year's Palm Sunday, which commemorates Jesus Christ's return to Jerusalem, are burned to produce ashes. The ashes are a reminder that life on Earth ends.

During Ash Wednesday mass, a worshiper receives the ashes in the shape of a cross on the forehead, a cleric typically says, "Remember man is dust, and unto dust you shall return."

It is believed that Ash Wednesday observances began in the Catholic Church as early as 960. The burning of palm fronds became a tradition beginning in the 12th century. 

Ash Wednesday is not considered a holy day of obligation, but is one of the most important days in Lent. 

Christians are asked to give something up for Lent, often alcohol or another indulgence, starting on Ash Wednesday through Lent.

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