The Byzantine Empire was founded by Constantine the Great after he moved his capital to Constantinople (modern-day Istanbul). The empire survived for over 1,000 years and became one of the most powerful political entities in Europe for most of its history.
The Byzantine Empire was very different from its predecessor, the Roman Empire. It was located farther east than Rome had been, so it had a more diverse population than Rome did. Also, Constantinople was built on seven hills like Rome, but these hills were not as high or steep as those in Rome.
The empire’s economy relied heavily on agriculture and manufacturing; however, trade was also important because Constantinople was located along important trade routes between Europe and Asia.
The Byzantine Empire had a stronger focus on trade than the Romans did because they wanted to keep their ports open so they could trade with other countries safely without being attacked by pirates or pirates themselves attacking ships full of goods being sold abroad.
The Roman army was made up of professional soldiers who served for 25 years before retiring with a pension or retiring voluntarily at age 50 so they could continue to serve their country in civilian life. The Byzantine army consisted of conscripts who were required to serve for 3 years before being discharged into civilian life or could volunteer for another 2 years service if they wished to do so (but this would mean they would be ineligible for promotion).