Seven of the sentences (including the example) contain historical errors. Guess

Seven of the sentences (including the example) contain historical errors. Guess which ones are wrong and rewrite them with a negative past simple form.

1) Alexander the Great married Cleopatra.
Alexander the Great didnt marry Cleopatra..
2) Nelson Mandela became President of South Africa in 1994. ..
3) Leonardo da Vinci invented the Internet. ..
4) Confucius the Chinese philosopher died in 1900. ..
5) Marco Polo stayed in China for five years. ..
6) The ancient Romans used steam engines in their battles.
7) Genghis Khan invaded Italy and captured Rome.
8) Christopher Columbus reached America by accident.
9) William Shakespeare wrote Don Quixote. ..