Origins of the Church at Philippi

'The Church in Philippi is a result of Paul's ministry during his second Missionary Journey. The first convert in Philippi was a proselyte of Judaism, Lydia a business woman from Thyatira. (Acts 16:12-14) Her own conversion led to the conversion of her whole household. The opening of her home to the missionaries provided a base of operation for Paul's work and a place of assembly for the young church.'

(Taken from http://www.abu.nb.ca/ecm/Phip00b.htm) check it out for even more info about Philippians.