cats first domesticated humans at least since 7500 BCE, when the inhabitants of a neolithic village on Cyprus gave a feline (not native to the island) a ceremonial burial. What we know call the domestic cat was more truly feral when it split off from the African wildcat (Felis silvestris lybica), much earlier, some 10,000 years ago. They likely enjoyed a symbiotic relationship with humans -- proving their usefulness to the Natufians of the Levant by preying on mice whilst ignoring (since they are obligate carnivores) the Natufians' mouse-attracting stores of grain.
African wildcats in the wild (image source: Seasons in Africa)
Eventually cats moved were promoted from rodent catcher to household members and even divine beings. In Egypt cats were sacred and associated with the goddesses Isis, Mafdet (also spelled Maftet), and Bastet (also known as Baast, Ubaste, and Baset). The Greek historian Herodotus wrote that when a cat died, Egyptians would go into mourning, shaving their eyebrows to mark the loss of a family member. Cats were famously mummified and afforded dignified (by human standards) burials in Egypt. In 1888 a farmer discovered a tomb outside Beni Hasan which contained the mummies of about 80,000 cats (and some other animals).
Neolithic grave with a human and a cat (left) and mummified Egyptian cats (right)
The reverence afforded to cats in ancient North Africa probably strikes most humans today as excessive and strange. However even the most insensitive amongst us usually react with repulsion, horror, and indignation when they learn that in places like Guangdong, Guangxi, Japan, Korea, Melmac, Mparntwe, Okinawa, Peru, Switzerland, cats have traditionally been eaten or used in medicine. It seems a bit rich to me when coming from people who think nothing of eating a fish, bird, cow, or pig.
In placs where felines are off the menu they have inspired artists like the 9th Century Irish monk who wrote, "Pangur Bán," Gioachino Rossini, T.S. Eliot, Saki, Hiroyuki Morita. Although there were famous cats before the advent of the internet (e.g. Room 8 of Elysian Heights), it might appear to aliens observing our planet that it was invented to honor them -- the modern incarnation of feline worship passed down from ancient Egypt. Our modern pantheon includes Ceiling Cat, Happy Cat, Grumpy Cat, Hipster Kitty, Keyboard Cat, Lil Bub, Maru, Missy the Cat, Nekopan, Nyan Cat, and Snoopybabe, to name but a few.