A Medieval relief representing Pentecost. Sculpted between 1360-1363 by Bartomeu de Robió, one of the best Catalan sculptors of the Gothic style group known as the Lleida School. This piece used to be part of the altar in Lleida's cathedral. It was there for 400 years, until the 18th century when, after the Castillian army occupied Catalonia and as part of the new Spanish monarchy's militarization and punishment of Catalonia, Lleida's cathedral was turned into army headquarters and the population who lived in the hill slopes was expelled. In that moment, the retable that included this piece was disassembled and dispersed. Source: Lleida Museum.
Today is Pentecost, also known in English as Whit Sunday and in Romance languages as Second Easter. It's one of those holidays where in some places it's a day off but most people don't know exactly what it is that we're supposed to be celebrating...
Pentecost means "the 50th day" in Greek, because it's a holiday celebrated 50 days after Easter Sunday. Since it depends on the date of Easter, it follows the moon calendar and falls on a different calendar day every year. Even though it's not widely celebrated by the public like other holidays related to religion like Christmas, Corpus, Carnival or Easter, the Pentecost is an important feast days in most Christian churches, including the Catholic, Orthodox, Lutheran and Anglican churches.
The Pentecost celebrates two things. First, it commemorates the Jewish holiday called the Feast of the Weeks or Shavuot. This holiday is held on the day in which it's believed that God gave Moses the Ten Commandments (the tables that say the basic laws of Jewish and Christian religions). Secondly, it commemorates the event 50 days after Jesus Christ's resurrection in which, according to the Christian belief, the Holy Spirit descended to Earth while the Twelve Apostles, the Virgin Mary and other followers were together celebrating Shavuot. This symbolizes the formation of the new Church: Christianity. For this reason, Pentecost is considered the most important Catholic religious celebration after Easter, Corpus and Christmas.