13 people killed after a van is driven into crowds in Barcelona. How do we keep our cities safe from these kinds of attacks?
15 March 2016, 16:14
Since Boris became Mayor of London, dull moments have been few and far between - here are the best bits of his time in charge.
From his famous sporting prowess to his killer dance moves, via "whiff whaff" and Arnie, Boris has never been less than entertaining.
Our video showcases the most talked-about moments of Mr Johnson's time in charge - is your favourite there?