E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
or All Hallows. In 610 the Pope of Rome ordered that the heathen Pantheon should be converted into a Christian church, and dedicated to the honour of all martyrs. The festival of All Saints was first held on May 1st, but in the year 834 it was changed to November 1st. Hallows is from the Anglo-Saxon hálig (holy).