Le code and Qing dynasty system of China, most scholars regard it as being a near-complete copy of the Qing code. The code was later translated into French by Paul-Louis-Félix Philastre. It focused on strengthening the power and authority of the emperor, his mandarins, and the traditional family unit. In cases of serious crimes, particularly those against the state, collective punishment was meted out to the family of the convict, including the death penalty. Now that Vietnam was unified, the center of gravity of the country moved further south, following centuries of southerly migration and conquest, so Gia Long moved the seat of government from Hanoi to Huế. Gia Long rebuilt the old citadel of Phú Xuân into a fortress stronghold. The structure was a square shape of 2.5 km per side. A 9 m rampart was encased with masonry and protected by protruding bastions, each defended by 36 guns. The exterior and interior were flanked and reinforced by a series of moats. The citadel's defenders included an 800-strong elephant troop. The new palace structure, protocol and court dress were all taken directly from Qing dynasty styles, and his palace and fortress was intended to be a smaller copy of the Chinese Forbidden City in the 1800s. Gia Long tolerated the Catholic faith of his French allies and permitted unimpeded missionary activities out of respect to his benefactors. The missionary activity was dominated by the Spanish in Tonkin and French in the central and southern regions. At the time of his death, there were six European bishops in Vietnam. The population of Christians was estimated at 300,000 in Tonkin and 60,000 in Cochinchina. However, he expressed dismay at the Catholic condemnation of the traditional ancestor worship, a basic tenet of Vietnamese culture. Gia Long was also known for his disdain for Buddhism, the religion practiced by the majority of the population. Despite its popularity among ladies of the court, Gia Long often restricted the activities of Buddhists. In August 1802, Gia Long retaliated against the captured Tây Sơn leadership who had executed his family in the 1770s. The surviving members of the family and its leading generals and their families were executed. The remains of Quang Trung and his queen were exhumed and desecrated, and his son, the last Tây Sơn monarch Quang Toản was bound to four elephants and torn apart. Gia Long repealed the changes enacted by Quang