Through mighty signs and wonders, by the power of the Spirit of God; so that from Jerusalem, and round about unto Illyricum, I have fully preached the gospel of Christ. Through mighty signs and wonders - This more fully explains the preceding clause: through the power of the Holy Ghost he was enabled to work among the Gentiles mighty signs and wonders; so that they were fully convinced that both his doctrine and mission were Divine; and therefore they cheerfully received the Gospel of the Lord Jesus.
Round about unto Illyricum - Among ancient writers this place has gone by a great variety of names, Illyria, Illyrica, Illyricum, Illyris, and Illyrium. It is a country of Europe, extending from the Adriatic gulf to Pannonia: according to Pliny, it extended from the river Arsia to the river Drinius, thus including Liburnia on the west, and Dalmatia on the east. Its precise limits have not been determined by either ancient or modern geographers. It seems, according to an inscription in Gruter, to have been divided by Augustus into two provinces, the upper and lower. It now forms part of Croatia, Bosnia, Istria, and Slavonia. When the apostle says that he preached the Gospel from Jerusalem round about to Illyricum, he intends his land journeys chiefly; and, by looking at the map annexed to the Acts of the Apostles, the reader will see that from Jerusalem the apostle went round the eastern coast of the Mediterranean Sea, and that he passed through Syria, Phoenicia, Arabia, Cilicia, Pamphylia, Pisidia, Lycaonia, Galatia, Pontus, Paphlagonia, Phrygia, Troas, Asia, Caria, Lycia, Ionia, Lydia, Thrace, Macedonia, Thessaly, and Achaia; besides the isles of Cyprus and Crete. And no doubt he visited many other places which are not mentioned in the New Testament.
I have fully preached the Gospel - Πεπληρωκεναι το ευαγγελιον, I have successfully preached - I have not only proclaimed the word, but made converts and founded Churches. See the note on Matthew 5:17, where this sense of the word πληρουν is noticed; for it signifies not only fully or perfectly, but also to teach with prosperity and success.