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Leadership  Team

About: About
About: Team

Andrew Mackay CBE


Andrew Mackay is co-founder of Complexas and is responsible for the development and implementation of Complexas' strategy and narrative. He has been involved in the stabilisation of fragile and conflict-afflicted states throughout his career. These have included NI, Lebanon, Bosnia, Kosovo, Iraq, and Afghanistan.

Andrew has worked extensively across sub-Saharan Africa. His principal focus has been on providing decision support to the resolution of complex political and social problems that delay the progress of a range of projects. This also includes the tools required to understand communities, the resolution of social conflict and the implementation of sound ESG practise.

Andrew has written and co-authored a number of papers and books that address the challenge of understanding politics and communities in complex environments, including Behavioural Conflict: Why Understanding People and Their Motivations Will Prove Decisive in Future Conflict. 

David Wombell


David Wombell is co-founder of Complexas and is responsible for the delivery of all operational tasks and senior consultancy relationships. He has worked extensively in sub-Saharan Africa, the Middle East, and Asia over the last twenty-five years, developing a wide network of business, government and institutional contacts. 

David has been especially active in Africa since 2010, completing projects in Mozambique, Burkina Faso, Côte d’Ivoire, Ghana, Guinea, Mali, Nigeria, Senegal, Zambia, South Africa and Sierra Leone.

Before co-founding Complexas, David held a senior Business Development position at Baobab Investments and prior to this  served as an Officer in the British Armed Forces.


David holds an MA in International Defence Studies from King's College London, as well as an MBA.

Sheila Khama 

Senior Advisory Board Member

Sheila Khama is an independent consultant, a minerals, oil and gas policy advisor, an author, and podcast host, with more than two decades’ work experience. She is a former executive of Anglo American Corporation and De Beers Groups in Botswana. Sheila has extensive knowledge of the mining industry, the Africa business environment and sustainability challenges in mineral, oil and gas industries. She has worked for the World Bank and African Development Bank’s mineral, oil and gas policy advisory units, leading teams of experts advising governments in Africa, Latin America and Central Asia.


Sheila is a non-executive director of Tullow Oil, an FTSE 250 company, a board member of the Mandela Institute of Development Studies and the Development Partner Institute. She serves on the Sustainability Panel of LafargeHolcim, the Advisory Boards of Columbia University Centre for Sustainable Investments, the UN Sustainable Development Solutions Networks, and the Audit Committee of the UN Office of Operations. Sheila is a former CEO of De Beers Botswana and served as a non-executive director of several companies including the world’s largest producer gem diamonds by value, Debswana. She has served on the Sustainability Panel of AngloGold Ashanti, and the Technical Committee of Oxford University’s Natural Resources Charter among others. Sheila has lived and worked in Botswana, Ghana, Ivory Coast, Tunisia, the UK and USA.

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