Shufang () to Luoyang to scout it, but Pei was discovered, and the Sui officials at Luoyang began to prepare for an attack. In response, Li and Zhai launched their assault at Luokou Storage (), a massive food storage that Emperor Yang built, and they captured it. They opened the food storage to allow the people to take food, and many people joined them. The Sui generals Liu Changgong () and Fang Shi (), viewing Zhai's forces as nothing more than bandits looking for food, took them lightly and attacked. Li and Zhai wore out the army from Luoyang with hunger, and then attacked, defeating it. Later, Li held a feast for Zhai Rang and then assassinated Zhai. As Duke of Wei In the aftermaths of the battle, Zhai Rang supported Li Mi as leader and offered the title of Duke of Wei—a title that Li's grandfather Li Yao () had previously carried during Northern Zhou—to Li. Li accepted, and changed the era name to show independence from Sui. Li made Zhai his prime minister and created him the Duke of Dong Commandery. Once Li made his declaration, the rebel generals of the region largely submitted to him, and much of modern central and eastern Henan came under Li's rule. However, after Sui reinforcements arrived from Jiangdu under the command of Wang Shichong, Li's advances, while initially successful over Wang as well, became stalled. By fall 617, Pei Renji had surrendered to him as well. Also joining him were Qin Shubao and Cheng Zhijie (). Despite the increasing number of followers, however, Li continued to be unable to capture Luoyang. When Chai Zhaohe () suggested to him—in accordance with his own suggestion to Yang Xuangan years earlier—that he commission Zhai and Pei to remain near Luoyang to keep the Luoyang troops checked, while he himself lead a surprise attack against Chang'an, Li responded that without capture Luoyang first, his followers would not be convinced that they could prevail, and so he did not accept Chai's suggestion. Meanwhile, another Sui general named Li—Li Yuan the Duke of Tang, who had been in charge of Taiyuan (太原, roughly modern Taiyuan, Shanxi) to guard against Eastern Tujue's attacks—rebelled at Taiyuan, claiming that he wished to support Emperor Yang's grandson Yang You the Prince of Dai, then nominally in charge at Chang'an, emperor. Li Yuan initially wrote Li Mi, trying to see if Li