The genitive of adjective refers to specification and is seen in english as in/with. Usually applies to “full, empty rich, poor, lots, many”, they denote desire, knowlege, memory, fullness, power, sharing, and guilt (Latintutorial)
The city was filled with lots of people who hated the emperor : Urbs plumebat cum multi populi invisibant imperatorem.
The tomb was full of gold and the mans favorite foods: Sepulcrum erat pleni auri et viri delicata cibi.
Julius Caesar was determined for military success : Iulius Caesar deliberabat victoriae militaris.