I knew I wanted to write about female friendship. I've got a few friends I've known since we were teenagers, who have spanned the decades, and I do find that a fascinating thing, that friendship can last that length of time.

Navratilova won an astounding 167 singles titles and 166 doubles titles in a career which has spanned nearly 30 years. She changed the game of women's tennis by forcing opponents to reach her standards of fitness and athleticism.

Science for hundreds of years has spanned the differences between cultures and between countries.

My marriage had been impulsive. That marriage should have been short-lived instead of the 23 years it spanned.