(also known as All Hallows' Day or Hallowmas ) is a major Christian solemnity celebrated on November 1st in Western Christianity and the first Sunday after Pentecost in the East . It is dedicated to honoring all the saints of the church, both officially canonized figures and the "uncounted multitude" of unknown souls believed to have attained eternal life in heaven. Historical Origins
The feast emerged from the early Christian tradition of honoring martyrs on the anniversaries of their deaths. All Saints
: Pope Gregory IV extended the feast to the entire Western Church in 837 AD. (also known as All Hallows' Day or Hallowmas
: In the 8th century, Pope Gregory III moved the celebration to November 1st. Some historians suggest this was to coincide with or supplant pagan harvest festivals like the Celtic Samhain . : Pope Gregory IV extended the feast to