The Revd Mark Oakley, Canon Chancellor of St Paul's Cathedral explains what's behind the exhibition.
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The happy couple said they did not know about a high-profile social media campaign to find them until they got back from honeymoon.
On Sunday night in Stratford he'll try and break what's known as the Hour Record - racing laps of the velodrome for 60 minutes.
Disruption was expected to last well into the rush hour, threatening a repeat of chaotic scenes at London Bridge earlier this year.