Complex sentence: Written by English scholars, the first twelve volumes dealt with the history of the world from 1450 up to 1910: the final volume, numbered 12, was "The Latest Age" and appeared in 1910.
Split into simpler sentences: Written by English scholars, the first twelve volumes dealt with the history of the world from 1450 up to 1910. The final volume, numbered 12, was "The Latest Age" and appeared in 1910.