Mufasa+Simaba Fan is correct. Each Lion King film was based on Shakespeare.

Actually its Kimba the white lion. And yeah, from screenshots you can see similarity... and few story similarities, but also a lot of differences, didn't took almost nothing from here... and Simba originally was going to be white and Kimba lives in jungle and guess what original title was The King of the Jungle. I watched almost all episodes of Kimba, old version. But Disney denies this, stating they had no clue about Kimbas existence. In my opinion, thats what happened, when Disney originally started production of TLK, Company who made Kimba went bankrupt. There were a lots of companies interested in it, the most interested at time was Disney, but didn't get it at the end, there were some lawsuits I think. But they probably already started on TLK project. And later(still early in production) decided not to throw it away, but to change it, when they knew they can't do Kimba. So they would be able to release it.

But for me is enough to say it is the source of idea, to make another animal movie with lions and mix it with Shakespeares Hamlet. Actually all TLK movies(1, 2, 3(a.k.a 1 and 1/2)) take storys from Shakespeare. Disney has a lot of animated movies taking stories from legends or old works, nobody can lawsuit them for. I wonder, if Kimba was their little mistake they had to deny. But even so, TLK movies are too good to really blame them too much.

I think this cartoon was out a while ago called Kimba the Lion and it gave them an idea.Also Kimba and Simba rhymn

I'm not entirely sure but here is my answer.
Disney always used the rule "one Disney film a year" so they felt they had to make one film before Pocohauntus which was orginally the film everybody wanted to do.
Someone came up with a vauge idea of Lion King which in very early stages was called The King of the Jungle. (Then they realized there were no lions in the jungle! )
Lion King was nicknamed "Bambi in Africa with Hamlet thrown in." They based Lion King around Hamlet, and old Bible Tales like Moses and Joseph. Hope this helps!