Who wrote the four ancient poems?

Zhang Xu's "Four Ancient Poems" was written in ink, with five-color notes and cursive script. Length 28.8 cm, width 192.3 cm. Every 40 lines, 188 words. No money, Ming Dong Qichang for zhang.

The whole stroke is full, without delicate and slippery strokes. The handwriting is ups and downs, moving and static, full of paper like a cloud, which is really the peak of cursive writing. Modern Guo Zixu said: "Four ancient poems can be said to be the crystallization of Zhang Xu's life, the typical beauty of genius and nature, the essence of national art and the symbol of eternal beauty." (China Calligraphy Appreciation Dictionary)

Now it is collected by Liaoning Provincial Museum.