Tidjane Thiam an executive director, sitting on the plc board. In January 2007, after Richard Harvey announced he would step down as chief executive of Aviva, Thiam was tipped as a possible future head of the group. Thiam left Aviva in September 2007 to become chief financial officer of Prudential plc. In March 2009, Thiam was named chief executive, effective from October, after Mark Tucker chose to step down. The appointment made him the first African to lead a FTSE 100 listed company. His departure from the role was announced on 10 March 2015. After he became chief executive, Prudential launched a
Boots UK Rudd. The CEO Richard Baker left, and the new group became Alliance Boots plc. The merger became effective on 31 July 2006. Alliance Boots was purchased by Kohlberg Kravis Roberts and Stefano Pessina, the deputy chairman of the company, in April 2007 for £11.1 billion, taking the company private and beating a rival bid from Guy Hands' Terra Firma Capital Partners. This was the first ever instance of a FTSE 100 company having been bought by a private equity firm. In June 2008, the group headquarters were moved to Zug, Switzerland. According to John Ralfe, Boots' former head of corporate