In my WIP, my main setting is a city named Last Bastion (for historical reasons) that is very desirable for strategic commercial and militant reasons. It is saturated by magic, and is a cultural melting pot. Approximately 4.5 million beings live there. As a result of it's desirability, it has been attacked, seiged, and molested by bandits, pirates, and conquering armies very frequently since it's humble beginnings thousands of years ago. As a result, it is surrounded by tall, thick walls, it's food is brought in by portal from farms throughout the world, and it has a reasonable standing army, along with a militia made up of privately trained citizens. My question is, these conditions must have other effects on the city and it's inhabitants. What might they be?