Blackstone’s commentaries online (he doesn’t start English law in 1066).

BOTH thefe undertakings, of king Edgar and Edward the confeffor, feem to have been no more than a new edition, or frefh promulgation, of Alfreds’s code or dome-book, with fuch additions and improvements as the experience of a century and an half had fuggefted. For Alfred is generally ftiled by the fame hiftorians the legum Anglicanarum conditor, as Edward the confeffor is the reftitutor. Thefe however are the laws which our hiftories fo often mention under the name of the laws of Edward the confeffor; which our anceftors ftruggled fo hardly to maintain, under the firft princes of the Norman line; and which fubfequent princes fo frequently promifed to keep and to reftore, as the moft popular act they could do, when preffed by foreign emergencies or domeftic difcontents. Thefe are the laws, that fo vigoroufly withftood the repeated attacks of the civil law; which eftablifhed in the twelfth century a new Roman empire over moft of the ftates on the continent: ftates that have loft, and perhaps upon that account, their political liberties; which the free conftitution of England, perhaps upon the fame account has been rather improved than debafed. Thefe, in fhort, are the laws which gave rife and original to that collection of maxims and cuftoms, which is now known by the name of the common law. A name either given to it, in contradiftinction to other laws, as the ftatute law, the civil law, the law merchant, and the like; or, more probably, as a law common to all the realm, the jus commune or folcright mentioned by king Edward the elder, after the abolition of the feveral provincial cuftoms and particular laws beforementioned.

BUT though this is the moft likely foundation of this collection of maxims and cuftoms, yet the maxims and cuftoms, fo collected, are of higher antiquity than memory or hiftory can reach: nothing being more difficult than to afcertain the precife beginning and firft fpring of an antient and long eftablifhed cuftom. Whence it is that in our law the goodnefs of a cuftom depends upon it’s having been ufed time out of mind; or, in the folemnity of our legal phrafe, time whereof the memory of man runneth not to the contrary. This it is that gives it it’s weight and authority; and of this nature are the maxims and cuftom which compofe the common law, or lex non fcripta, of the kingdom.