<P> The Roman Catholic holy day of All Saints ( or All Hallows ) was introduced in the year 609 , but was originally celebrated on 13 May . In 835 , Louis the Pious switched it to 1 November in the Carolingian Empire , at the behest of Pope Gregory IV . However , from the testimony of Pseudo-Bede , it is known that churches in what are now England and Germany were already celebrating All Saints on 1 November at the beginning of the 8th century . Thus , Louis merely made official the custom of celebrating it on 1 November . James Frazer suggests that 1 November was chosen because it was the date of the Celtic festival of the dead ( Samhain ) -- the Celts had influenced their English neighbours , and English missionaries had influenced the Germans . However , Ronald Hutton points out that , according to Óengus of Tallaght ( d . ca . 824 ) , the 7th / 8th century church in Ireland celebrated All Saints on 20 April . He suggests that the 1 November date was a Germanic rather than a Celtic idea . In the 11th century , 2 November became established as All Souls ' Day . This created the three - day observance known as Allhallowtide : All Hallows ' Eve ( 31 October ) , All Hallows ' Day ( 1 November ) , and All Souls ' Day ( 2 November ) . </P>
the christian church used which holiday to take attention away from samhain
All Saints ( or All Hallows )