There has never, so far as I've been able to establish, been such a period in recorded history. Laws have always been essential to maintain society and defend individuals against others. Laws are among the earliest known writings, wherever settled communities grew up. Known examples of formal legal systems date back to Mesopotamian records from 2830 BCE.
In Britain, formal legal systems do not begin with the Roman Invasion; rather, there is evidence that various systems existed prior to that and some of these were merged into the Romano British system. The Roman system survived through the subsequent migrations and invasions until the Norman Feudal system took its place. This was, in turn, supplemented by the Common Law, which now exists in parallel with Parliamentary Statute Law.