Why is the Ma-Xia school named after Ma Yuan and Xia Gui?

The Ma-Xia school is named after Ma Yuan and Xia Gui because these two artists were the most prominent members of the Southern Song imperial painting academy to define and master the school’s signature style.12

Active during the late 12th and early 13th centuries, Ma and Xia are credited with the fullest expression of a landscape aesthetic designed to evoke a sense of limitless space and atmospheric void. Their collaborative influence established the school's hallmark features, most notably the "one-corner" composition—an asymmetrical arrangement that leaves large portions of the silk or paper bare—and the use of "ax-cut" brushstrokes, which are characterized by angular, staccato movements that mimic the marks of an ax or chisel on wood. Because their lyrical and dramatic interpretations of nature became the definitive model for this artistic movement, the group was collectively named in their honor.12