1. The Inscription of the Epistle. Achaia as it was in the time of Saint Paul.
This Epistle was also inscribed to the same recipients as the former, to the Corinthians or τῇ ἐκκλησίᾳ τοῦ Θεοῦ τῇ οὔσῃ ἐν Κορίνθῳ, to the Church of God which is at Corinth, and also τοῖς ἁγίοις πᾶσι τοῖς οὖσιν ἐν ὅλῃ τῇ Ἀχαΐᾳ, to all the saints which are in all Achaia, 2 Corinthians 1:1. Now, at the time that the Apostle wrote, Achaia was extending quite broadly in the Peloponnese and beyond, having Corinth and Athens as metropolises, in which latter in particular it was called ἑλλὰς/Greece, Acts 20:2. And Achaia was extending as broadly as the citizens bound to the Achæan league were extended.
 Acts 20:2: “And when he had gone over those parts, and had given them much exhortation, he came into Greece (εἰς τὴν Ἑλλάδα)…”  The Achæan League, which included almost the entire Peloponnese, was defeated by the Romans at the Battle of Corinth (146 BC), and ultimately disbanded.