Short answers, pulled from the story.
Roman legions destroyed the city of Corinth in 146 BC, marking the end of Greek independence for mainland territories. This event concluded a series of conflicts known as the Macedonian Wars that had seen Rome slowly gaining control.
Augustus reorganized the peninsula as the province of Achaea in 27 BC while later reforms under Diocletian shifted boundaries during the late third century. Theodosius subsequently divided the Macedonian prefecture into smaller provinces named Creta, Achaea, Thessalia, Epirus Vetus, Epirus Nova, and Macedonia.
Emperor Nero visited Greece in 66 AD and competed at the Ancient Olympic Games despite rules prohibiting non-Greek participation. He won every contest he entered before proclaiming freedom for Greeks at the Isthmian Games held in Corinth the following year.
The apostle Paul preached in cities including Philippi, Corinth, and Athens where Thessalonica became one of the most highly Christianized areas throughout the entire empire. Greek language served as a lingua franca in eastern provinces and Italy itself during this religious transformation.
Alaric and his Goths migrated toward Italy where they sacked Rome in 410 AD after entering Greek territories freely with the permission of Eutropius. They looted Athens, Corinth, and the Peloponnese region without immediate resistance before Stilicho drove them out around 397 AD.