Analysis of information sources in references of the Wikipedia article "História das bandeiras cristãs" in Portuguese language version.
Legend states that a red cloth with the white cross simply fell from the sky in the middle of the 13th-century Battle of Valdemar, after which the Danes were victorious. As a badge of divine right, Denmark flew its cross in the other Scandinavian countries it ruled and as each nation gained independence, they incorporated the Christian symbol.
The Portugal man-of-war (1182) and merchant flags (1183 and 1184) bore the same distinguishing features— five shields with the five circles representing the five wounds of Christ, the castles surrounding the inner shields and the armillary sphere, reminiscent of that nation's maritime prowess in the sixteenth century, 200 years ago, as they do now.
In 1968 the Methodist Men of Broad Street purchased flags to be used in the sanctuary of the Church. This involved one United States flag, one Christian flag, flag poles, stands, one eagle and one cross.
Miss Fanny J. Crosby, the veteran American hymn writer, has dedicated a hymn, called “The Christian Flag,” to the movement, the first verse of which is :— “ The Christian Flag!
The Moravians created a seal. The seal has a picture of a sheep holding a cross with the Christian flag attached. It says, “Our lamb has conquered. Let us Follow Him.” This symbolizes Jesus conquering sin, and the Moravian’s commitment to follow Him.
