Note 1 at Ac 16:14: Lydia was a merchant from Thyatira (see note 2 at this verse) in Lydia of Asia. She was Paul's first convert in Europe, although her hometown was in Asia. She was already a worshiper of God before Paul shared the Gospel with her. This verse implies that Lydia was the only woman of the group who received the Gospel, and it specifically states that the Lord opened her heart so that she listened to Paul's words.

Ac 16:15 and 40 mention Paul and Silas entering into Lydia's house in Philippi. This, along with the fact that Ac 16:15 mentions her household being converted, leaves no doubt that she had a residence in Philippi. The residents of Thyatira were famous for their skill in the dyeing of purple, and this is no doubt where Lydia became associated with her trade of the selling of purple. Therefore, there is a definite link between Philippi and Thyatira, and she may have maintained residences in both cities.

It is evident from Re 1:11 and 2:18-24 that Thyatira had a Christian church. Since the Scriptures don't mention Paul ministering in Thyatira, it is possible that Lydia is the one the Lord used to introduce the Gospel to that town.

Note 2 at Ac 16:14: Thyatira was a city in the province of Asia (see note 3 at Ac 16:6) on the edge of Lydia. It was on the road between Pergamum and Sardis. The people of Thyatira were well known for their skill in the dyeing of purple, and Lydia, a seller of purple, came from there. There is no record of Paul ministering in Thyatira, but a Christian church was established there (Re 1:11 and 2:18-24), possibly from Lydia's witness or others that Paul had evangelized in Asia.