Sir Frederick Pollock reports, http://oll.libertyfund.org/simple.php?id=2313,

Latin as a legal language. During the century that follows, Latin keeps its preeminence, and when, under Henry II. and his sons, the time comes for the regular enrolment of all the king’s acts and of all the judgments of his court, Latin becomes the language of our voluminous official and judicial records. From this position it is not dislodged until the year 1731, when it gives place to English. It were needless to say that long before that date both French and English had been used for some very solemn, perhaps the solemnest legal purposes; but seemingly we may lay down some such rule as this, namely, that if a series of records goes back as far as the twelfth or the first half of the thirteenth century, it will until the reign of George II. be a series of Latin records. It is only in the newer classes of authoritative documents that either English or French has an opportunity of asserting its claims. French becomes the language of the privy seal, while Latin remains the language of the great seal. French expels Latin and English expels French from the parliament rolls and the statute rolls, but these rolls are new in Edward I.’s day. In particular, Latin remains the language in which judicial proceedings are formally recorded, even though they be the proceedings of petty courts. In Charles I.’s day the fact that the Star Chamber has no proper Latin roll can be used as a proof that it is an upstart.