“Charm us, orator, till the lion look no larger than the cat.”

tr. O'Neill 1938, Perseus http://www.perseus.tufts.edu/hopper/text.jsp?doc=Aristoph.+Thes.+529
Thesmophoriazusae (411 BC)

The Reader's Digest, Volume 121 (1982), p. 118.
Attributed

What is to be Done? (1902)

Christopher Soames, speech at the Reform Club (28 April 1981), reported in Martin S. Gilbert, Winston S. Churchill. Volume Eight: Never Despair: 1945–1965. p. 304
Post-war years (1945–1955)
Variant: I like pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.
Context: [Christopher Soames, Churchill's future son-in-law, remembered] Churchill showing him around Chartwell Farm [around 1946]. When they came to the piggery Churchill scratched one of the pigs and said: I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.

Techelles, Act I, scene ii, line 132
Tamburlaine (c. 1588)

1850s, The House Divided speech (1858)
Context: There are those who denounce us openly to their own friends and yet whisper us softly, that Senator Douglas is the aptest instrument there is with which to effect that object. They wish us to infer all this from the fact that he now has a little quarrel with the present head of the dynasty; and that he has regularly voted with us on a single point upon which he and we have never differed. They remind us that he is a great man, and that the largest of us are very small ones. Let this be granted. But "a living dog is better than a dead lion." Judge Douglas, if not a dead lion, for this work, is at least a caged and toothless one. How can he oppose the advances of slavery? He does not care anything about it. His avowed mission is impressing the "public heart" to care nothing about it. A leading Douglas Democratic newspaper thinks Douglas's superior talent will be needed to resist the revival of the African slave-trade. Does Douglas believe an effort to revive that trade is approaching? He has not said so. Does he really think so? But if it is, how can he resist it? For years he has labored to prove it a sacred right of white men to take negro slaves into the new Territories. Can he possibly show that it is less a sacred right to buy them where they can be bought cheapest? And unquestionably they can be bought cheaper in Africa than in Virginia. He has done all in his power to reduce the whole question of slavery to one of a mere right of property; and as such, how can he oppose the foreign slave trade — how can he refuse that trade in that "property" shall be "perfectly free" — unless he does it as a protection to the home production? And as the home producers will probably not ask the protection, he will be wholly without a ground of opposition.

Source: Black Blood

Attributed to Napoleon in Napoleon (1941) by Yevgeny Tarle, this is a variant of an ancient proverb often attributed to many military and political figures, including Alexander the Great, and the even earlier figure Chabrias (Χαβρίας).
Misattributed

Attributed to Alexander, as quoted in The British Battle Fleet: Its Inception and Growth Throughout the Centuries to the Present Day (1915) by Frederick Thomas Jane, but many variants of similar statements exist which have been attributed to others, though in research done for Wikiquote definite citations of original documents have not yet been found for any of them:
I should prefer an army of stags led by a lion, to an army of lions led by a stag.
Attributed to Chabrias, who died around the time Alexander was born, thus his is the earliest life to whom such assertions have been attributed; as quoted in A Treatise on the Defence of Fortified Places (1814) by Lazare Carnot, p. 50
An army of stags led by a lion would be better than an army of lions led by a stag.
Attributed to Chabrias, A History of Ireland (1857) by Thomas Mooney, p. 760
An army of stags led by a lion is superior to an army of lions led by a stag.
Attributed to Chabrias, The New American Cyclopaedia : A Popular Dictionary of General Knowledge (1863), Vol. 4, p. 670
An army of sheep led by a lion are more to be feared than an army of lions led by a sheep.
Attributed to Chabrias, The Older We Get, The Better We Were, Marine Corps Sea Stories (2004) by Vince Crawley, p. 67
It is better to have sheep led by a lion than lions led by a sheep.
Attributed to Polybius in Between Spenser and Swift: English Writing in Seventeenth Century Ireland (2005) by Deana Rankin, p. 124, citing A Contemporary History of Affairs in Ireland, from 1641 to 1652 (1880) by John Thomas Gilbert Vol. I, i, p. 153 - 157; but conceivably this might be reference to Polybius the historian quoting either Alexander or Chabrias.
An army composed of sheep but led by a lion is more powerful than an army of lions led by a sheep.
"Proverb" quoted by Agostino Nifo in De Regnandi Peritia (1523) as cited in Machiavelli - The First Century: Studies in Enthusiasm, Hostility, and Irrelevance (2005) by Mathew Thomson, p. 55
Greater is an army of sheep led by a lion, than an army of lions led by a sheep.
Attributed to Daniel Defoe (c. 1659 - 1731)
I am more afraid of one hundred sheep led by a lion than one hundred lions led by a sheep.
Attributed to Charles Maurice de Talleyrand-Périgord (1754 – 1838) Variants: I am more afraid of an army of 100 sheep led by a lion than an army of 100 lions led by a sheep.
I am not afraid of an army of one hundred lions led by a sheep. I am afraid of army of 100 sheeps led by a lion.
Variants quoted as an anonymous proverb:
Better a herd of sheep led by a lion than a herd of lions led by a sheep.
A flock of sheep led by a lion was more powerful than a flock of lions led by a sheep.
An army of sheep led by a lion would defeat an army of lions led by a sheep.
It were better to have an army of sheep led by a lion than an army of lions led by a sheep.
An army of sheep led by a lion, will defeat an army of lions led by a sheep.
An army of sheep led by a lion would be superior to an army of lions led by a sheep.
Unsourced attribution to Alexander: I would not fear a pack of lions led by a sheep, but I would always fear a flock of sheep led by a lion.
As one lion overcomes many people and as one wolf scatters many sheep, so likewise will I, with one word, destroy the peoples who have come against me.
This slightly similar statement is the only quote relating to lions in The History of Alexander the Great, Being the Syriac Version of the Pseudo-Callisthenes (1889) as translated by E. A. Wallis Budge, but it is attributed to Nectanebus (Nectanebo II).
Disputed