Li Guangbi, the martyr's descendant, didn't behave like an ordinary child since his childhood. From a young age, he excelled in horsemanship and archery. He had a stern and resolute character, rarely smiling or joking. People felt a sense of awe upon seeing him, and everyone in the military knew he was a promising young talent with great ambitions. After the death of Li Kailuo, Li Guangbi inherited his father's title. He served under Wang Zhongsi, the Military Governor of Hexi, as the commander of the cavalry and the leader of the Chishui Army. Wang Zhongsi had a keen eye for talent and treated Li Guangbi differently. He often said, "In the future, the one who can lead my troops can only be Guangbi." Due to his repeated military achievements in defeating the Tubo and Tuyuhun forces, the Tang court promoted Li Guangbi to General of Cloud Banners.
At that time, An Sishun, the Military Governor of Shuofang, recommended Li Guangbi as his deputy and entrusted him with the management of military logistics. Due to Li Guangbi's talents and straightforwardness, An Sishun wanted to arrange a marriage between his daughter and Li Guangbi. However, Li Guangbi declined, claiming he was unwell, thus avoiding this marriage proposal. This indicates that Li Guangbi had a strategic vision from the beginning of his career and aimed to avoid entanglement in the webs of power and relationships among influential officials and generals. This way, he could remain devoted to the court and resist personal temptations and favors. His rival, Ge Shuhan, who had a strained relationship with An Sishun, learned about this and admired Li Guangbi's principles. At that time, An Lushan and An Sishun held significant power, making it nearly impossible for ordinary people to curry favor with them. Li Guangbi's unwavering integrity and determination set him apart. In response, Ge Shuhan praised Li Guangbi's exceptional integrity and submitted a petition to the court, bringing Li Guangbi to the capital as a military officer.
