Kate Middleton showed strength during her relationship's tense moment with Prince William.

The couple broke up in 2007 and reunited later after setting out some guidelines.

The split made Kate stronger and helped her understand herself better.

Prince William got it wrong and re-evaluated their relationship after the break-up.

Kate set out some rules that showed her strength of character.

Their friendship is the secret to their success and a solid base for their relationship.

Kate's behavior during the split made her a no-brainer for future queen, according to a royal expert.

She was considered a good girl who handled herself well throughout their dating history.

Kate's behavior during the break-up showed she was not going to be messed around.