What happened on November 1 ?

Roman festivals - last day of the Ludi Victoriae Sullanae.

Catholicism - Holy Day of Obligation, All Saints Day. Holiday in Austria, Belgium, Croatia, France, Germany, Hungary, Italy, Lithuania, Mexico, The Philippines, Poland, Portugal, Seychelles, Slovenia, Spain, Guatemala.

Also see November 1 (Eastern Orthodox liturgics)

Algeria - National day

Antigua and Barbuda - Independence Day (from Britain, 1981)

Ireland - Samhain the traditional first day of Winter

Mexico - The Day of the Dead

World Vegan Day

United States - Start of National Novel Writing Month