“Wherever Law ends, Tyranny begins.”

A Voice Crying in the Wilderness (Vox Clamantis in Deserto) (1990)

A Vindication of Natural Society (1756)
Context: A good parson once said, that where mystery begins, religion ends. Cannot I say, as truly at least, of human laws, that where mystery begins, justice ends? It is hard to say whether the doctors of law or divinity have made the greater advances in the lucrative business of mystery. The lawyers, as well as the theologians, have erected another reason besides natural reason; and the result has been, another justice besides natural justice. They have so bewildered the world and themselves in unmeaning forms and ceremonies, and so perplexed the plainest matters with metaphysical jargon, that it carries the highest danger to a man out of that profession, to make the least step without their advice and assistance. Thus, by confining to themselves the knowledge of the foundation of all men's lives and properties, they have reduced all mankind into the most abject and servile dependence. We are tenants at the will of these gentlemen for everything; and a metaphysical quibble is to decide whether the greatest villain breathing shall meet his deserts, or escape with impunity, or whether the best man in the society shall not be reduced to the lowest and most despicable condition it affords. In a word, my Lord, the injustice, delay, puerility, false refinement, and affected mystery of the law are such, that many who live under it come to admire and envy the expedition, simplicity, and equality of arbitrary judgments.

Speech at Bristol Previous to the Election (6 September 1780)
1780s

Surefish interview (2002)

Remarks at the Dedication of the Thomas J. Dodd Archives and Research Center in Storrs, Connecticut http://www.presidency.ucsb.edu/ws/index.php?pid=50654&st=tyranny&st1=destruction, October 15, 1995
1990s

As quoted in With Prejudice : The Perspective of an Acquitted Defendent (2010) by Vicky Gallas; no earlier occurence of this phrasing has been located (Relevant quote: "Il n’y a point de plus cruelle tyrannie que celle que l’on exerce à l’ombre des lois et avec les couleurs de la justice" i.e. "There is no tyranny more cruel than that which is exercised within the shade of the law and with the colours of justice." See Chap. XIV of Considérations sur les causes de la grandeur des Romains et de leur décadence).
Disputed

Speech to the thirtieth anniversary of the Junior Imperial League in Kingsway Hall (19 June 1926), quoted in Our Inheritance (London: Hodder and Stoughton, 1938), pp. 17-18.
1926
Context: You have to realize that these years in which we are living, the years into which we are entering, are going to be, as no years before have been, the real testing-time of democracy... We in this country may make a fearful mess of it; and if we make a mess of it, we shall get something much worse— we shall get a tyranny of some kind or other. I don't know what form of tyranny it may be. It may be the communist tyranny; it may be tyranny from the other end. But if you cannot evolve a sound and sane democracy, that will be the fate of the country.

speech at Lord Mayor’s Luncheon, Mansion House, London, November 10, 1942 : ( partial text http://www.churchill-society-london.org.uk/EndoBegn.html)
Referring to the British victory over the German Afrika Korps at the Second Battle of El Alamein in Egypt.
The Second World War (1939–1945)
Variant: This is not the end, this is not even the beginning of the end, this is just perhaps the end of the beginning.
Source: Their Finest Hour

Source: Dash & Lily's Book of Dares