Commentaries on the Laws of England are an treatise on the common law of England by Sir William Blackstone. The Commentaries are considered as the leading work on the development of English law and also they played a great role in the development of the American legal system. The Commentaries were influential mainly because they were in fact readable, and because they met a need. The work is as much an apologia for the legal system of the time as it is an explanation; even when the law was obscure, Blackstone sought to make it seem rational, just, and inevitable that things should be how they were.