Good Friday is the most solemn day of the church year. Elements of the liturgy for this day date from the fourth century, and are based on practices that were observed during Holy Week at various holy sites in Jerusalem.
Good Friday is part of the Paschal Triduum, the series of observances that begins with Maundy Thursday, continues today and Holy Saturday, and culminates with the Great Vigil and the celebration of the Lord’s resurrection.