Westminster Abbey organised a series of lectures and events to commemorate the bicentenary. These included the lectures 'Olaudah Equiano, Black Abolitionist' by Professor Vincent Carretta, and 'The Abbey and the Abolition of the Slave Trade' by The Reverend Nicholas Sagovsky, Canon of Westminster. There was also an opportunity for visitors to attend William Wilberforce's memorial. On 27 March 2007 a national service of commemoration was held at the Abbey, and broadcast live on BBC One and BBC Radio Four. The service was attended by HM The Queen, the Prime Minister Tony Blair, other dignitaries and members of community and human rights organisations. Proceedings were disrupted by Toyin Agbetu of the Pan African, human rights based organisation Ligali. He objected to the celebratory tone of the service and its primary focus on William Wilberforce, highlighting the role of African freedom fighters and the absence of an official apology by the monarchy, government and church for Britain's leading role in transatlantic slavery, or Maafa (the Kiswahili term meaning ‘Disaster’, which is used to refer to the exploitation of Africa and its people by Europeans).