Although Paul's final letter was most likely II Timothy, Paul's epistles are not arranged chronologically in the New Testament. Instead, they are arranged from longest to shortest in two batches, first his letters to churches and second to individuals. Thus, after his letters to Timothy, we pick up with a fresh missive to another disciple of Paul: Titus.
Unlike Timothy, we don't know too much about Titus. There is a lot of speculation regarding his appearances in other books of the New Testament (is he Titius Justus in Acts 18:7? is he an unnamed companion of Paul on his travels?)
But we do know from this letter that Titus is stationed in Crete, placed there at Paul's direction for the purpose of appointing leaders (bishops or elders) in each of the towns in the area (vs. 5). What follows in chapter 1 is a list of the qualifications of elder (very similar to what we read in I Timothy) - as well as some disparaging remarks about Cretans!
One gets the sense from reading Titus 1 that Paul is in the thick of contending for the faith. He needs his helpers, good men like Titus and Timothy, to approve the right leaders for the church. Paul particularly desires mature Christian believers, above reproach, who can preach and teach adequately. Paul is also concerned with the "circumcision party" and their agenda to spread their corrupted version of the faith.