The practical application of the rights of immediacy was complex; this makes the history of the Holy Roman Empire particularly difficult to understand, especially for modern historians. Even such contemporaries as Goethe and Fichte called the Empire a monstrosity. Voltaire wrote of the Empire as something neither Holy nor Roman, nor an Empire, and in comparison to the British Empire, saw its German counterpart as an abysmal failure that reached its pinnacle of success in the early Middle Ages and declined thereafter.[4] Prussian historian Heinrich von Treitschke described it in the 19th century as having become "a chaotic mess of rotted imperial forms and unfinished territories".