to small shallow barges (after passing the Huai River and having to cross southwestern Shandong), then transferred back to large river barges on the Yellow River before finally reaching Beijing. With the necessary tribute grain shipments of four million shi (one shi equal to 107 liters) to the north each year, both processes became incredibly inefficient. It was a magistrate of Jining, Shandong who sent a memorandum to the Yongle Emperor protesting the current method of grain shipment, a request that the emperor ultimately granted. The Yongle Emperor ambitiously planned to move his capital to Beijing. According to a popular legend, the capital was moved when the emperor's advisers brought the emperor to the hills surrounding Nanjing and pointed out the emperor's palace showing the vulnerability of the palace to artillery attack. The emperor planned to build a massive network of structures in Beijing in which government offices, officials, and the imperial family resided. After a painfully long construction time (1407–1420), the Forbidden City was finally completed and became the imperial capital for the next 500 years. The Yongle Emperor finalised the architectural ensemble of his father's Xiaoling Mausoleum in Nanjing by erecting a monumental "Square Pavilion" (Sifangcheng) with an eight-metre-tall tortoise-borne stele, extolling the merits and virtues of the Hongwu Emperor. In fact, the Yongle Emperor's original idea for the memorial was to erect an unprecedented stele 73 metres tall. However, due to the impossibility of moving or erecting the giant parts of that monuments, they have been left unfinished in Yangshan Quarry, where they remain to this day. Even though the Hongwu Emperor may have meant for his descendants to be buried near his own Xiaoling Mausoleum (this was how the Hongwu Emperor's heir apparent, Zhu Biao was buried), the Yongle Emperor's relocation of the capital to Beijing necessitated the creation of a new imperial burial ground. On the advice of fengshui experts, the Yongle Emperor chose a site north of Beijing, where he and his successors were to be buried. Over the next two centuries, thirteen emperors in total were laid to rest in the Ming tombs. Religion and philosophy The Yongle Emperor was a Chinese traditionalist. He promoted Confucianism, retained traditional ritual ceremonies, and respected the classical culture, overhauled numerous Taoist temples and monasteries in Mount Wudang dedicated to Zhenwu Dadi. During his reign, many Buddhist and Taoist temples were built. The Yongle Emperor sought to