Changing China: John Simpson returns to Tiananmen Square

China is preparing for a major change in its top political leadership in the autumn, with President Hu Jintao and other senior leaders stepping down after 10 years in charge.

President Hu has overseen a decade in which China has become the driving force of the world's economy, creating a middle class now estimated at 300m people.

The BBC's World Affairs editor John Simpson returned to Tiananmen Square in Beijing to reflect on how China has changed in the last 10 years.