It is believed that Ebru water marbling has been in existence since the 15th Century. At that time, it was used on decrees from royalty. This prevented any forgeries or modifications to the documents.
It is said that when the paint was spattered on the water, using a rose stem and perhaps horse hair, the artists were attempting to capture the look of stones under the water. Some say they were trying to capture the clouds in the sky. Whichever it was, a beautiful form of art was born.
Once paper was more readily available and books were still hand-stitched, marbled pages were used as end pages to hide the mechanics. Knowledge of how to marble was very closely held and many marblers only knew one step of the process. Thus, it took a team of people to create each sheet of paper. Keeping the process secret nearly allowed the art form to disappear.
Water marbling and its cousin, suminagashi, made their way through Turkey and India, into Europe and marbling is said to have arrived in the United States in the 1700s, with Benjamin Franklin experimenting with marbling the United States currency. Marbling regained popularity in the United States in the early 1980s.
End pages became obsolete when the bookmaking process became more mechanized and pages were glued into their bindings. The beautiful pages were no longer necessary.
Ebru has come a long way since its inception. We now have synthetic gall and do not have to use the actual bile from the gall bladder of an ox (something I cannot even imagine). We have a rainbow of colors that are easily floated and enough ideas to try, that one could marble for days and weeks at a time, without covering every idea.