For example and in my personal opinion:

Nicholas II Romanov, the last Czar of Russia.
Nicholas was a good man in my opinion. A devoted husband and father, but a terrible ruler.

Nicholas saw his role as monarch rather religiously, considering himself responsible only before God and ignored cries for a constituonal monarchy. His inability to relate to his people and to the time he lived in resulted in disasters such as Bloody Sunday or War with Japan.
He even allowed a man like Rasputin into Court, sullying Imperial reputation:

Nicholas was unable to adapt to the times, and thus paid the terrible price.

Lenin merely took the opportunity, exploiting Czar’s many failures to bring himself to power after overthrowing Kerensky which led to the creation of Soviet Union and many infamous crimes of the regime that followed. One of the first was:

The horrible fate of Imperial family haunted me for a while. The brutal murder of a monarch and his loved ones, not because he was an evil man but an incompetent leader.
He is canonized today as a saint, as well as his entire family. But such tragedy indeed.
This may be offensive or even enjoyable for some people as I am about to completely change your perspective on certain historical figures.
1. GANDHI
Probably one of the most peaceful men of all time, today seen as a true hero in India, hated by the British in the 30’s and 40’s for his independence movement, was a SEX addict.
At age 38, he took an official vow of chastity (refraining from sexual intercourse), He tested his resistance trough unusual, creepy ways. His preferred method was to sleep with women, way younger than him, completely naked. Some even say during his death’s father, he was burying the weasel with his wife. Of course, every other Indian had to strictly respect the tradition of sex only after marriage.

(good for independence, bad for keeping his hands away from underage girls)
But in the end, Gandhi died of syphilis, which is a very ironic thing.
2. CHURCHILL
Oh yea, we have an Indian and a British fella in the same answer. Highly linked as you might expect.
Of course, Churchill the savior of Europe, the man who kept the morale up. But also a little bit racist. In his 20’s, 30’s, he took part in wars in Africa against colonies who wanted independence.
Once he declared, when asked about the Kurdish situation, : “I am strongly in favor of using poisoned gas against uncivilized tribes, it would spread a lively terror.”
Oh and let’s not forget about the hatred for Indians and the famine of 1943, which some say it’s justified, some say not. The fact is that 3 million Indians died.

3. JOBS
This man truly revolutionized the industry and made smartphone technology what is today, but too bad he is only remembered for that!
He was the first to sign up contracts to have access to China’s workforce and plant the first-ever Apple factory in China. The first factories, however, had very bad working conditions, so bad that certain employees killed themselves because of the conditions, working hours and low pay.
There is also a hugely unknown scandal of Apple stocks, basically he wrote himself as the owner of some stock long time before the actual date and buying them at whatever price he wanted (CEO privileges) The result was him cashing in by selling them at a much higher price.

4. CHAPLIN
Ah yes, the beloved comic actor of the inter-war period, he was no different that the first man from this answer.
Two out of his four wives were under 18 when he married them, one was 18 and one 22 years old.( he was in his 50s when he married his last wife, 18 years old)
Chaplin married his first wife because he thought she was pregnant (false alarm), Mildred Harris was a young actress at that time but Charlie was very unsupportive of her, claiming ‘’she is too young to have any real talent’’
Then there’s the second marriage, even more disastrous, the divorce papers show the poor treatment of his second wife, Lita Grey. He had sexual intercourse with her when she was 16 and he was 35. They married because abortion failed.
Grey was often cheated on by Chaplin with younger actresses, paid very little attention to his children. Grey divorced him in 1927, getting 825.000$. Too little for the scars he left.

I hope I opened your eyes a little bit about these very known historical figures!