Arrian, "The Campaigns of Alexander the Great" (Fourth Century B.C.E.), published in Katharine J. Lualdi, Sources of The Making of the West, Vol. I: To 1740, Third Edition (Boston: Bedford / St. Martin's, 2009), pp. 79-83
Eratosthenes, "Measurement of the Earth" (Third Century B.C.E.), published in Katharine J. Lualdi, Sources of The Making of the West, Vol. I: To 1740, Third Edition (Boston: Bedford / St. Martin's, 2009), pp. 93-95
Julius Caesar, "The Gallic War" (52 B.C.E.), published in Katharine J. Lualdi, Sources of The Making of the West, Vol. I: To 1740, Third Edition (Boston: Bedford / St. Martin's, 2009), pp. 116-119
Greece's expansion into the area surrounding the Mediterranean Sea wasn't as much an effort in conquest as it was of unification, unlike Rome's building of a republic that would become an empire.
Alexander the Great's efforts to expand Greece's territory incorporated cultures and lands south into Egypt and as far east as into India. His campaigns lasted eleven years until his death in 323 B.C.E. and his empire fell into petty squabbling as his generals each tried to get their own piece of Alexander's kingdom. Alexander managed to keep his kingdom together through the use of garrisons in each conquered country as well as keeping the local governments in power. The conquered peoples noticed little change in their daily lives after the battles as they were still dealing with the same governing bodies.
Leaving the garrisons in the conquered countries had a two-fold effect. One, it kept the peace and a small reminder that they were a conquered people, and two, it gave two separate cultures a chance to intermingle and learn from each other. Alexander also brought scholars with him on his conquests, to record information about his campaigns, and to record new discoveries -- new to Alexander and the Greeks. Thus knowledge was shared: knowledge of other peoples, other flora and fauna not native to the Mediterranean, and knowledge of other religions, which impacted the Romans later as they adapted a lot of Greek gods but gave them Roman names: Zeus became Jupiter, Hera became Juno, Athena was Minerva in Roman, to name a few.
When Caesar, among other Roman generals, were expanding Rome's influence in a more northerly direction into Europe, a similar occurrence happened with the cross-culture exchange.
This cross-culture exchange expanded thoughts and ideas into music, philosophy, art, theater, science and law.
In Arrian's "The Campaigns of Alexander the Great," the author tells of the time when Alexander had returned to Persia from India when his soldiers desired to return home. Alexander decided to send home the disabled veterans to appease some of the homesickness. His Macedonian soldiers resented this move as they feared the Persians were to be taking their place.
Alexander delivered a speech that inspired the men to realize that his men came before himself. He did what he did for them. It wasn't his glory, it was their glory. It wasn't his treasure, it was their treasure.
After his speech, Alexander retired to his palace, cloistering himself for three days before summoning his Persian officers to bestow on them command of Alexander's armies. When the Macedonians heard of this, they prostrated themselves in supplication, offering up the soldiers who led the efforts of returning home, for a chance to stay by his side. Alexander relented and accepted their apologies, offering up a sacrifice to the gods. He also hosted a banquet for the men, Persian and Macedonian alike, to bring them together as the army of Alexander, not Persian soldiers and Macedonian soldiers. This shared affiliation bonded the men and they shared aspects of their culture as a result.
Besides bringing distant and diverse cultures together through his army, Alexander also had the world's largest library built in the city named for him, Alexandria. Scientists and scholars from across Alexander's empire were encouraged to come to the library to research new thoughts and processes to further technology and knowledge. One such man was Eratosthenes. He hypothesized that using two matching sundial bowls in the distant cities of Alexandria and Syene, both in Egypt about 500 miles apart, and measuring the length of the shadow cast by the sundial in one sundial where the other sundial has no shadow as the sun was directly overhead, he could calculate the circumference of the earth. The reason Eratosthenes used Syene was because the city was directly south of Alexandria, on the same meridian circle, or longitudinal line, and both cities had the same structure with the same height, very important in measuring the length of the shadows. Would this have been possible without Alexander's conquering of most of the known world around the Mediterranean? Highly doubtful as a lot of local tribes were still warring in a lot of areas that Alexander's armies invaded. Alexander's personal charisma helped people want to come together and share experiences and thus share their culture.
Alexander set the stage for Rome, with a cross-culture empire having already been established once. Alexander showed that, done correctly, people of varied cultures can get along and learn from each other. Once Rome began to rise in power and territory, they modeled some of their expansion techniques on Alexander's, including establishing towns of Roman citizens throughout conquered territories. While the towns comprised mainly of citizens and not garrisons of soldiers, the basic idea was similar in principle: leave people loyal to the conquerors in the territory of the conquered.
In the account of Julius Caesar finishing his conquest of the Gauls in what later became France, it is mentioned how Caesar rewarded his friends and generals with governorships in areas he had conquered, specifically Commius who was awarded the Kingship of Atrebates and Brutus -- the same one who later was one of Caesar's murderers and the subject of the now famous line "Et to, Brute?" -- was awarded the governorship of Transalpine Gaul. This was yet another way of putting Roman influence into area outside of Rome -- in the manner that Alexander had done with his empire some two centuries beforehand -- spreading the culture, as well as absorbing the local customs by the governorship and his aides.
The Romans also built roads connecting major cities in their new conquered nations. This shortened the time for troop movement between cities, but also helped ease travel for the citizenry. As time went on, and the Roman armies needed the use of the roads less and less, the locals used the roads more and more, giving an ease of travel to greater distances, farther than most have traveled before. Local customs became wider spread and incorporated into larger areas. Knowledge was traded along the roads as well, as travelers carried it with them wherever they went.
