First Referenced:
'I was told that everyone I'd served with in the military died shortly after I left. (Part 4)'
Earth 44 is a desert variant of Earth, where The Ink was first encountered. Earth 44 was being used by The First World as a source of resources, resulting in ongoing conflict with "Rebels", likely inhabitants of that specific reality.
How exactly The Ink and the Shadow Sphere ended up on Earth 44 is currently unknown.