How did common law come to be practiced as the accepted "norm

The common law so named because it was "common" to all the king's courts across England originated in the practices of the courts of the English kings in the centuries following the Norman Conquest in 1066. The form of reasoning used in common law is known as casuistry or case-based reasoning.

i think its 5! hope i

i would say the executive branch is because the executive branch is in charge of enforcing the laws and judicial branch is in charge of enforcing but the executive branch is most responsible for it all so i would have to say the executive branch.