This Day in Christian History - November 25 The Deluge , by John Martin , 1834. Oil on canvas. Yale University November 25, 2348 B.C. - Noah's Flood Begins Archbishop James Ussher's Old Testament chronology records that the "Great Deluge" of Noah's flood commenced on this day. According to Genesis 7, " all the fountains of the great deep were broken up, and the windows of heaven were opened. And the rain was upon the earth forty days and forty nights."