I've actually watched the oldest surviving video. It's a couple of seconds long and show a person in a garden.
The oldest one I've actually watched for entertainment purposes was a Haunted Castle or House of the Devil from the late 1890s.
George Melies! I seen it too. Lasts maybe 5 minutes, at most.
Thats the one where a cross kills the demon guy- or wtf he is-right? It's been called the first vampire movie. It's not.