Overview
Pauls first letter to the Churches at Corinth had been undermined by "false teachers". They had portrayed Paul as arrogant; unqualified; unattractive and dishonest.
Paul sent Titus to Corinth to deal with this and rejoiced when Titus returned with news that many had repented and accepted Pauls authority. Paul then wrote this second letter to that majority and to the rebellious minority who still refused to accept his leadership.
In this letter Paul emphasises his own conduct and calling as an Apostle. He defends himself against the criticism which had been levelled against him. Paul had been arranging collections of goods for the "saints in Jerusalem" and had asked the Corinthians to contribute in his first letter. In this letter he spends considerable time on the responsibility and reward of Christian giving.
Author
The apostle Paul
Time of 2nd Corinthians
This needs to be seen in the context of the first letter. Paul sent Titus to Corinth to talk with the people and Paul went to Macedonia (probably Philippi) to meet Titus on his return.
Here, in Macedonia, in late AD56, Paul wrote his second letter to the Corinthian Church prior to visiting the church himself where he wrote his letter to the Roman Church