As these areas of law became more complex in tandem with the society that they governed, Roman rulers found themselves in need of a larger group of legal authorities to give order to the system of legal formulas and decisions. By the second half of the third century BCE, a new professional group of specialists trained in law, the jurists, emerged to meet this demand. The jurists did not participate in administering the law, but rather focused on interpreting and generating formal opinions on the law, as the pontiffs had done in earlier days. It was the work and scholarly writings of generations of great jurists that elevated Roman law to its apex during the first two and a half centuries CE, which is referred to as the classical period of Roman law.