It is always assumed that it was “Paul’s mission to the Gentiles” however in the letter considered to be Paul’s first (1 Thessalonians) it opens with:

“Paul, Silvanus, and Timothy,

To the church of the Thessalonians in God the Father and the Lord Jesus Christ:“

The letter uses the words “we” and “us”, appearing to imply that the three were a team working to gain converts. 

2 Corinthians opens with:

“Paul, an apostle of Christ Jesus by the will of God, and Timothy our brother,

To the church of God that is in Corinth, together with all the saints throughout Achaia:”

This seems to imply an elevated role for Paul than in 1 Thessalonians, but then (in the only other mention of Silvanus in an authentic letter) Paul writes as if the three of them proclaimed the message of Jesus: 

“For the Son of God, Jesus Christ, whom we proclaimed among you, Silvanus and Timothy and I, was not “Yes and No,” but in him it has always been “Yes.”

It’s always seemed odd to me that Paul was so successful traveling by himself to convert Gentiles, but it makes more sense if he started out as a team. Thoughts?