Victoria was born in 1819 in the middle of a succession crisis. Queen Victoria, the only child of George III's fourth son, Edward, and sister of Leopold, king of the Belgians, was queen of Great Britain for 63 years (longer than any other British monarch and the longest of any female monarch in history). Queen Victoria's reign saw advances in industry, science (Charles Darwin's theory of evolution), communications (the telegraph, popular press) and other forms of technology, thanks to the fact that Britain had become a nation of town dwellers. In this period, the Victorian cities were famous for their squalor, disease and crime; the morality rate was hight and terrible working conditions in polluted atmospheres had a disastrous effect. Epidemics like cholera and tuberculosis spread and killed so many people. Anyway, medicine also underwent a radical change: professional organisations were founded to regulate and control medical education and research, and modern hospitals were built. Moreover, even now Victorian institutions, prisons, police stations, boarding schools and towns halls can still be seen in British cities.