The Roman Empire was centered on continuous expansion. This created an extremely strong sense of achievement and national pride through the military prowess carried out in the world's best army. Roads were created between major cities, and in each city conquered by Rome, Roman law was implemented (HST Lecture 318: The Roman Empire – Part I). This has created a standard mindset that everyone can follow, which has helped unify the population as a whole and created common needs for innovation to address. However, the Romans themselves would not accept the change; instead, they imposed the change on others. This innovation was considerably limited because the spread of ideas foreign to the Roman road was not taken with sincerity. Nonetheless, the Romans were very successful in terms of innovation, and being a Roman citizen reaped these benefits. The wealthiest citizens could even acquire running water, a feat made possible by transporting water from mountainous regions by aqueducts, an engineering marvel spurred by the desire for luxury (HST Lecture 318: The Roman Empire – Part I). Luxury was a new concept in Rome, where people simply purchased items, not out of necessity, but out of a desire to gain higher social status. People began to really care about what others thought of them and their lifestyle, which boosted the economy and prompted the creation of need-based products. Markets developed and the Roman economy