During the early years of the Sung dynasty, two distinct styles of landscape painting developed, which today are known as "Northern" and "Southern," reflecting their geographical locations. Although it is extremely dangerous to venture generalizations about painting schools, it might be said that the Northern school produced comparatively formal, symmetrical works done in sharp, angular, ax-like brushstrokes which distinguished clearly between ink line and ink wash and in which the distant mountains were generally portrayed as crisply as the foreground. In contrast, the Southern school as a rule preferred a more romantic treatment of landscape elements, with rounded hills and misty valleys. Distant mountains were portrayed in graded washes of ink, suggesting mysterious recesses bathed in fog, while the middle ground was filled with rolling hills mellowed by a sense of diffuse lighting. A Chinese critic of the period described a Northern artist's work as all brush and no ink, and a Southern artist's as all ink and no brush--a simplified but basically accurate characterization of the two schools. The Northern style was originally centered around the northern capital of Kaifeng and the Southern around Nanking in the Yangtze valley, but when the Sung court fled to the South after the fall of the northern capital in 1127, the styles of the two schools were merged to some degree in a new academy that was established in the lovely southern city of Hangchow. Painters of the Southern Sung dynasty, as this later era came to be known, often were masters of both styles, sometimes producing jagged Northern landscapes, sometimes misty Southern vistas, or sometimes combining the two in a single painting. In time, however, as the mood of the age grew increasingly romantic and Ch'an Buddhism became more influential in academic circles, the jagged brushstrokes of the Northern painters retreated farther and farther into the mist, leaving the landscapes increasingly metaphorical, with contorted trees and rugged, textured rocks.