The Union Jack
The Union Jack has been the paramount ensign of Britain and her company of nations ever since the period of their phenomenal worldwide expansion. The first "Jack" came into use when James VI of Scotland became king also of England in 1603. It then comprised the age-old English flag of St. George, a square red cross on a white ground, combined with the diagonal white cross on a blue ground, combined with the diagonal white cross on a blue ground of Scotland's St. Andrew. The "Jack" as we now have it dates from 1801 when Ireland was incorporated with Britain and St. Patrick's diagonal red cross on a white ground completed the present flag.
The term "Jack" was applied in deference to King James, the Latin form of which is Jacobus, the equivalent in Hebrew being Jacob. The full meaning of the term "Union Jack" may therefore truly be construed as the Union of Jacob. If this is a coincidence, it is indeed a remarkable one, for Jesus Christ endorsed the positive scriptural prophecy to the effect that there would be a union of the clans of Jacob before the end of the age.
The colours red, white and blue have significance for the Christian, for these were the colours used in the linen curtains of the tabernacle, precursor of the Temple. The blue background is of particular interest, for when speaking through Moses God commanded the people of Israel to keep throughout their generations a "ribband of blue" as a reminder of the need for obedience to His commandments.
The Twelve Tribal Emblems
Source: ' Voice of Revival'