The Holy Roman Empire always walked a fine line with total disintegration. A collection of almost, but not-quite autonomous city-states, baronies, princedoms, bishoprics and miscellaneous other political units, which ranged in size from literally a few city blocks to a few thousand square miles (or square kilometers, if that's your thing), all of differing degrees of power, allegiance to each other, and religious, ethnic and ideological orientations, united by a vague allegiance to an elected (though not democratically in any modern sense) Emperor, whose powers would be overstated by calling them purely symbolic.

Internal politics in the Holy Roman Empire ranged from byzantine to totally incomprehensible, as alliances between statelets rose up, shifted and collapsed over the course of months or even weeks. This suited the more unified foreign powers with interests in the Empire rather well indeed, since the feuding statelets were easy to manipulate, and after the Thirty Years War, which was mostly fought on Holy Roman Empire soil, and which some historians claim was so devastating it set the Empire back a hundred years, this diffusion of power was codified at the Peace of Westphalia.

The upshot of this was that Germany, as a modern state, would not materialize until the late 19th century, later than any other Western European state except Italy, which had problems of its own. The catalyst for the unification of Germany was the ascencion of Prussia, and more specifically the Junker class of Prussian landowners, as the unparalled regional power, and the subjection of the rest of Germany to Prussian rule.