I was reading the reading Mugglenet, when I found this interesting theory that I had never thought of before. I think it is definatly a possibility.

"Well now that we have the long awaited title for the sixth book in the series, everyone is buzzing with one question "Who is the half blood Prince". Now, I know that this will probably make me about as popular as ragweed but I feel that there is a strong possibility that the Half Blood Prince is none other than Harry's cousin Dudley Dursley."

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