"Under Octavian Greece continued to be ruled as one province of Macedonia. However, in 27 B.C. Achaia became a senatorial province in its own right. This new administrative area, under the governorship of a proconsul, consisted of an area which incorporated the Peloponnese, Attica, Boeotia, Aetolia, Thessaly and part of Epirus" (Book of Acts in its Graeco-Roman Setting, Chapter 12).
Cities in the Province
Cities mentioned in the New Testament located within Achaia include Athens (Acts 17:15 - 16, 22, 18:1), the administrative center of the province named Corinth (Acts 18:1, 19:1, etc.), and Cenchrea (Acts 18:18, Romans 16:1, 27). Also located in this area is the famous city of Sparta that was known for its prowess in war.
Center of Paul's Evangelism
Achaia was one of the four Roman provinces the Apostle Paul focused the majority of his evangelist efforts. The other three provinces in which he spent the majority of his time were Asia, Macedonia (northern Greece) and Galatia.
Paul, during his second missionary journey, lives in and preaches in Corinth from late summer 50 A.D. to spring of 52. He spends, during his third evangelistic campaign, three months visiting churches in the province (Acts 20:1 - 3). While in Achaia He writes the first two of his fourteen New Testament books, first and second Thessalonians, between 50 and 51 A.D. He also pens the book of Romans from Corinth in late 57.
Church tradition states that the apostle Andrew died as a martyr in the city of Patrae found within the province of Achaia.