Bangkok became the capital of Siam (as Thailand was previously known) in 1782, when General Chao Phraya Chakkri, the founder of the ruling Chakkri dynasty, assumed the throne as Rama I and moved the court from the west to the east bank of the Chao Phraya River. The move appears to have been dictated by strategic considerations: the wide westward bend in the river constituted a wide moat guarding the northern, western, and southern perimeters of the new site. To the east stretched a vast, swampy delta called the Sea of Mud, which could be traversed only with extreme difficulty. Rama I modeled the new city on the former capital, Ayutthaya, 40 miles (64 km) to the north. By the end of his reign the city was established. The walled Grand Palace complex and the temple Wat Pho were completed. A new city wall, perhaps the most imposing structure, skirted the river and Khlong Ong Ang to the east; it was 4.5 miles (7 km) long, 10 feet (3 metres) thick, and 13 feet (4 metres) high, and it had 63 gates and 15 forts. The area enclosed amounted to 1.5 square miles (4 square km).