The title of my thesis is the rule of law and the British Constitution. For the sake of the transparency I divided my essay into two main parts. First I deal with the problem of the unwritten constitution in Britain which serves as an everyday debate among legal experts. To underline the two parts (those who support to have a written and those who propose to have an unwritten constitution) I demonstrate some opinions and the main reasons for and against it. Of course I further explain the historical background of the development of the constitution, to the better understanding of its today form. After this, I display the features and the characteristics of this document. In the second part of my essay I come to the principle of the rule of law. After a historical overview I briefly mention its connections to other principles. A. V. Dicey is the most important deputy of the rule of law notion and each British author mention him. Therefore I express his conception and I point to the failures of his theory.