One of the most popular theories is that after the Assyrians themselves were devastated by the Babylonians, their former Israelite captives migrated northwestward, eventually settling in what today includes Norway, Sweden, Denmark, Finland, the Netherlands, Belgium, France, Switzerland - and Britain. The British Israelites then, according to the theory, later expanded into what is today the United States, Canada, Australia and New Zealand.
According to the belief of many, those countries were founded by people of the Lost Ten Tribes of Israel, and are therefore the subject of end-time Prophecy that speaks of "Israel," which has a different meaning than "Judah." (see The Scepter and The Birthright and The Chosen People and Jews At War With Israel)
Jesus Christ directly instructed The Twelve Apostles to go to the "lost sheep of Israel" (e.g. Matthew 10:6). Did He mean just the single Israelite tribe of Judah, the Jews, that then inhabited the land of Israel, or did He mean what He actually said?
The Bible does not record the later travels of all of the apostles, or the entire travels of the apostles of those that it did. Paul, called after the Twelve, is accounted-for quite extensively, but even with him there was plenty of time for him to have been to other places.
One of the most curious non-Biblical accounts that have been used for reference to the possible travels of the apostles is the Sonnini Manuscript, which claims to account for Paul's journey to Britain and the continent (some refer to it as the "29th chapter of Acts," but it surely is not. Acts has 28 chapters, and we are warned by God not to add, or take away, anything from the Scriptures). Although perhaps fanciful in places, it does nevertheless provide an interesting, and generally possible, narrative for a journey that many are quite convinced did happen. A part of the text is shown here:
"And Paul, full of the blessings of Christ, and abounding in the spirit, departed out of Rome, determining to go into Spain, for he had a long time proposed to journey thitherward, and was minded also to go from thence to Britain. For he had heard in Phoenicia that certain of the children of Israel, about the time of the Assyrian captivity, had escaped by sea to "The Isles afar off" as spoken by the Prophet Ezra, and called by the Romans - Britain.
And the Lord commanded the gospel to be preached far hence to the Gentiles, and to the lost sheep of the House of Israel. And no man hindered Paul; for he testified boldly of Jesus before the tribunes and among the people; and he took with him certain of the brethren which abode with him at Rome, and they took shipping at Ostrium and having the winds fair, were brought safely into a haven of Spain.
And much people were gathered together from the towns and villages, and the hill country; for they had heard of the conversion to the apostle, and the many miracles which he had wrought. And Paul preached mightily in Spain, and great multitudes believed and were converted, for they perceived he was an apostle sent from God.
"And they departed out of Spain, and Paul and his company finding a ship in Armorica [some claim that this Old-World port was the origin of the word America] sailing unto Britain, they were therein, and passing along the south coast, they reached a port called Raphinus.
Now when it was voiced abroad that the apostle had landed on their coast, great multitudes of the inhabitants met him, and they treated Paul courteously and he entered in at the east gate of their city, and lodged in the house of a Hebrew and one of his own nation.
And on the morrow he came and stood upon Mount Lud and the people thronged at the gate, and assembled in the Broadway, and he preached Christ unto them, and they believed the Word and the testimony of Jesus. And at even the Holy Spirit fell upon Paul, and he prophesied, saying, Behold in the last days the God of Peace shall dwell in the cities, and the inhabitants thereof shall be numbered and in the seventh numbering of the people, their eyes shall be opened, and the glory of their inheritance shine forth before them. The nations shall come up to worship on the mount the testifieth of the patience and long suffering of a servant of the Lord.
And in the latter days new tidings of the Gospel shall issue forth out of Jerusalem, and the hearts of the people shall rejoice, and behold, fountains shall be opened, and there shall be no more plague. In those days there shall be wars and rumors of war; and a king shall rise up, and his sword, shall be for the healing of the nations, and his peacemaking shall abide, and the glory of His Kingdom a wonder among princes."
Fact Finder: Did Jesus Christ say that He too was sent only to the lost sheep of Israel at that time?