Winston Churchill was a British aristocrat and politician who served as First Lord of the Admiralty from 1911-1917 and Prime Minister in 1940-45 and 1951-55. Today he is remembered for his performance in the role of "courageous leader of beleaguered Britain" during World War II. That, most would argue, deserves praise.
 And the not-so-praiseworthy stuff
Churchill remains a controversial figure because of incompetent or brutal decisions made during the two world wars. He played a central role in planning the disastrous military campaign at Gallipoli[wp] during WWI, leading to a quarter-million Allied caualties. Worse, his decisions during the Second World War led to the fire-bombing of German cities by the Royal Air Force (the bombing of Dresden is one of the rare examples in which the American Army Air Corps joined the RAF in the purposeful incineration of German civilians). To be fair, however, Churchill later realized how horrific a war crime it was and expressed deep regret over this war strategy, likening it to "mutual annihilation," and lamenting a lost age of chivalry in warfare. Evidently, burning hundreds of thousands of non-combatants to death also serves as a massive blow to your pride.
He is remembered in India not only for that little famine in Bengal, but also for calling Gandhi a "half naked lunatic fakir." While in power and fighting for democracy, Churchill had every intention of holding onto India as a British colony.
Churchill was a racist and bought into eugenics. His charming response to the creation of the Jewish state of Israel was: "I do not apologize for the takeover of the region by the Jews from the Palestinians in the same way I don't apologize for the takeover of America by the whites from the Red Indians or the takeover of Australia from the blacks. It is natural for a superior race to dominate an inferior one." (This statement has has become even more awful in hindsight considering the nature of the Palestinian statehood debate.)
His further inability to accept the decline of the British Empire resulted a flurry of disastrous political games, most especially conspiring with Eisenhower and the CIA to depose Mohammad Mosaddegh, the democratically elected Prime Minister of Iran, and install in his place the Shah. This lead to the anti-Western blowback that created of the Islamic Republic of Iran.
 A famous quote
“”We shall go on to the end, we shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our Island, whatever the cost may be, we shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender, and even if, which I do not for a moment believe, this Island or a large part of it were subjugated and starving, then our Empire beyond the seas, armed and guarded by the British Fleet, would carry on the struggle, until, in God's good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the Old.
|—Speech in the House of Commons, 4 June 1940|