Eleanor Estes 
Miranda the Great [EPUB ebook] 

When barbarians invade Rome, Miranda the cat and her daughter Punka must find a safe place to hide from the chaos. They make their way through the burning city, collecting motherless kittens as they go. At last they reach the Colosseum–but even there, danger lurks! How these fortunate felines survive to become the noble ancestors of the cats of modern Rome is all due to the cleverness of the cat they come to call Miranda the Great, Queen of the Colosseum!