Prosperity and Decline, Petra
The Nabataean Kingdom was at its peek in the 1st centuries BC and AD. In this period, the Nabataeans held sway as far north as Damascus in Syria, as far south as Northern Arabia and also over parts of the Sinai and Negev deserts.
In 64 BC, Pompey arrived in the area with his Roman legions. He established the Roman province of Syria and encouraged the formation of the Decapolis league of city-states, which contained any further expansion by the Nabataeans.
The Nabataean Kings seem to have ruled as first among equals. The greatest of them was perhaps Aretas IV who ruled from 9 BC to 40 AD, when Petra boasted a population of some 30,000 people (if we include its outlying areas). However, Rome could not forever ignore the challenge to its power and influence and no doubt coveted the wealth of the city.
In 106 AD the Romans annexed the Nabataean Kingdom which became part of the Roman province of Arabia. Nabataean culture and language obviously did not disappear overnight, but it was around this time that many Roman-style improvements were made to the amenities in Petra. The Theater for example, was enlarged and the Colonnaded Street paved.
Throughout the 2nd century AD, Petra continued to flourish and there was an obvious synthesis of Greco-Roman and Nabataean elements in the buildings. However, once the Romans took control of the trade routes, diverting them away from Petra, the Nabataeans slowly but surely declined in wealth, power and creativity.