Board of Trustees

The American College of Sofia (ACS) is operated and funded by Sofia American Schools, Inc. (SAS), a non-profit, educational corporation chartered in 1926 in the United States by the Commonwealth of Massachusetts. As such, SAS is exempt from income taxes in the United States and contributions to it are tax deductible in the United States.

SAS was created for the sole purpose of providing education for Bulgarian youth. When it became impossible in the late 1940s for an American institution to function in Bulgaria, SAS obtained permission from the courts to spend the income from its endowment on education in non-Communist countries near Bulgaria, primarily Greece and Turkey. It returned to Bulgaria when conditions permitted and its sole function now is operating the American College of Sofia.

SAS is composed of members and trustees (who are also members). Members meet annually to hear reports and to elect members to three-year terms and trustees to one-year terms. Under its bylaws, all operating powers rest with the Board of Trustees. The Board of Trustees holds two regular meetings each year, one in the United States and one in Sofia, along with whatever special meetings are necessary. Its Executive Committee is empowered to act for the corporation between Board meetings.

Since the reopening of the College in 1992, the Board of Trustees has been chaired by Robert C. Hubbard, James E. Clayton, William J. Williams, Jr., Roger Whitaker, and, currently, Jonathan B. Clayton. Neither members of the corporation nor trustees receive any compensation for their services nor are they reimbursed for the costs of attending corporation or Board meetings. 

SAS has no office or employees in the United States. Its administrative work is contracted out to Educational Group Services, Inc., of Princeton, N. J., which does similar work for other American schools including Robert College and the American University in Beirut.

Meet the Trustees

Jonathan B. Clayton

Trustee since 2008
  • Juris Doctor, University of Virginia

  • Master of Business Administration, University of Texas

  • Bachelor of Arts, Economics, Princeton University

After serving as a Trustee for a decade, Mr. Clayton was elected by the trustees to serve as chair in 2018. His professional experience includes private law practice, management consulting with McKinsey & Company, and a technology startup, Arundo Analytics.

Christina E. Black

Тrustee since 2011
  • Master of Business Administration, New York University

  • Bachelor of Science, Applied Mathematics & Economics, Brown University

  • Budget Director in the Office of Management and Budget at Columbia University, New York City

Ms. Black’s grandfather, Floyd Black, was President of ACS (1926-1942), and her parents both served on the Board before the school re-opened. She joined the Board in 2011 and is currently Finance Committee Chair. Her professional experience includes Chief Budget Officer of the Metropolitan Museum of Art and her current position at Columbia University.

Avis T. Bohlen

Trustee since 2002
  • Bachelor of Arts, Radcliffe, Harvard (1961)

  • Master of Arts, Columbia University (1964)

  • Retired, former US diplomat

As a US Ambassador to Bulgaria (1996-1999), Ms. Bohlen was able to resolve some major issues with the Bulgarian government. After Ms. Bohlen retired, she was asked to join the ACS Board.

Ivelina Borisova

Trustee since 2018
  • Doctorate in Education, Harvard University, Graduate School of Education

  • Master's in Education, Harvard University, Graduate School of Education

  • Bachelor of Arts, Psychology and Art, Williams College

Ivelina is a global education adviser and leads UNICEF’s global portfolio in the area of early childhood education. She has worked extensively in low and middle-income countries on improving education policies and programs for children; in her role with UNICEF she supports governments to develop effective plans and finance quality early education. Ivelina is a member of the ’98 graduating class at ACS and is excited to contribute to the College.


Trustee since 2018
  • Doctor of Philosophy, Columbia University, in Comparative Politics and Education

  • Bachelor of Arts, University of Minnesota, History

  • Independent Consultant and Founder, Knowledge Without Borders Fund for educational philanthropy

Karen has a background in comparative politics with a focus on Eastern Europe and Russia. She is dedicated to improving socio-economic diversity in education through community engagement and philanthropy, and hopes to make a contribution to the exciting future of the American College of Sofia as a center of learning and leadership among young Bulgarians.

Ann Ferren

Trustee since 2010
  • Doctor of Education, Boston University

  • Master of Arts in Teaching, Harvard Graduate School of Education

  • Bachelor of Arts in Economics, Radcliffe College

After retiring from serving as Provost at the American University in Bulgaria from 2005 to 2010, Dr. Ferren was asked to join the ACS Board and continue her commitment to quality educational opportunities in Bulgaria. With expertise in curriculum and instruction, she spent 30 years as a faculty member and administrator at American University, Washington D.C. and Radford University in Virginia before coming to AUBG.

Nellie Gencheva-Gipson

Trustee since 2004
  • Master of Arts, New York University

  • Volunteer at the Metropolitan Museum of Art, New York City

Ms. Gipson joined the staff of the College for the second year of operation in 1993. She has a strong belief in education and its major effect on building a civil and democratic society.

Valentin Georgiev

Trustee since 2011
  • Master of Laws, Sofia University St. Kliment Ohridski

  • Pew Economic Freedom Fellow Program, Georgetown University

  • Executive Director, American Chamber of Commerce in Bulgaria

Mr. Georgiev has over 15 years of experience in the private sector as attorney at law and in the civil service as general secretary of the Bulgarian Parliament (1997-2001) and general secretary of the Central Election Committee, Bulgaria. His daughter graduated from the College in 2011.

Theodora Konetsovska

Trustee since 2012
  • Bachelor of Arts, Political Science & Economics, Williams College

  • Budget Director, Harvard University

Theodora is an alumna of the Class of 1997, the first graduating class after ACS’ reopening.

Nedko Kyuchukov

Trustee since 2013
  • Master of Business Administration (Baker Scholar - High Disctinction), Harvard Business School

  • Bachelor of Arts (Economics, Government), Dartmouth College

  • Partner, Westray Capital (hedge fund), London, UK

Alumnus of the ACS Class of 2003, Nedko helped establish the ACS Alumni Fund in 2011, and has served as the Chairman of the Alumni Fund Advisory Committee.

Tom Marshall

Trustee since 2019
  • Master of Education, Harvard University, Graduate School of Education

  • Master of International Affairs, Columbia University

  • Bachelor of Arts, Government and English, Hamilton College

  • Deputy Head of School, Jerusalem American International School

  • Director of Teaching & Learning, Walworth Barbour American International School in Israel

Tom Marshall served as Faculty Development Coordinator at the College from 2013 through 2016, and has worked as a teacher and administrator at schools in Europe, Asia, the Middle East, and the United States. His work as an education writer and journalist has been featured in publications including the St. Petersburg Times, the New York Times, and the Hechinger Report.

Ivo Panteleev

Trustee since 2005
  • University for Civil Engineering and Architecture, Sofia

  • Founding Partner, Architectural Design Agency Ltd. Sofia; Vice President of the Chamber of Architects in Bulgaria, and Chair of Foundation Friends Together, Sofia

Various contacts with the American College of Sofia since its reopening in 1992 have led to a deepening connection to the college and to his commitment and support of ACS in any possible fashion. Being the local architect of the new American Embassy in Sofia, he was recommended to join the Board of Trustees by US Ambassador to Bulgaria James Pardew in 2005. He also has a son and a daughter that graduated from ACS in 2004.

Evgenia Peeva

Trustee since 2011
  • Bachelor of Arts, Social Studies, Citation in Spanish, Harvard College

  • CEO at Teach For Bulgaria, a partner in the Teach For All network

Evgenia is an alumna of the ACS Class of 2004.

George Prohasky

Trustee since 2010
  • Doctor of Philosophy, International Economics, Academy of Sciences, Moscow

  • Chairman, Center for Economics Development; General Manager, Agromachina Ltd.

As a former Director of Open Society Foundation in Sofia, he was involved in the reopening of ACS after 1990. His elder son Mario is an ACS alumnus from the Class of 2001 and his other son, Slav, graduated from the College in 2014.

Marcie Ries

Trustee since 2016
  • Bachelor of Arts, Oberlin College

  • Master of International Affairs, Johns Hopkins School of Advanced International Studies.

  • Retired U.S. diplomat with thirty-seven years of service. International consultant specializing in Europe and leadership studies

Ms. Ries was U.S. Ambassador to Bulgaria from 2012-2015. During her tenure, the U.S. and Bulgaria concluded a strategic partnership agreement incorporating cooperation in many areas. Ms. Ries is committed to continuing to deepen the bilateral relationship and to supporting quality education for Bulgarian students via service on the Board.

Sam Seymour

Trustee since 2018
  • Bachelor of Arts, History, Dartmouth College

  • Juris Doctor, Columbia Law School

  • Lawyer, Sullivan & Cromwell LLP

Sam has a longstanding interest in independent secondary education and has served on the boards of several educational institutions. Past partners of Sullivan & Cromwell have served on the ACS board, and this connection brought Sam to Sofia and to ACS in 2018.

Borislav Stefanov

Trustee since 2018
  • Master of Business Administration, Harvard Business School

  • Master of International Management, Regents College

  • Bachelor of Arts, American University in Bulgaria

  • Management consultant and Founder of Hilltop 34 Boutique Advisory

Borislav is a member of the first graduating class, after the College reopened – Class of 1997. His professional background includes positions in the automotive industry (Daimler AG), management consulting (BCG), and private equity, as well as a 4-year period with InvestBulgaria, the government agency responsible for attracting and supporting multinational companies in Bulgaria.

Joel F. Studebaker

Trustee since 1980
  • Bachelor of Science, Chemistry, Stanford

  • Doctor of Philosophy, Chemical Physics, Harvard

  • Clinical data analyst at Janssen Pharmaceuticals/Johnson & Johnson

Mr. Studebaker’s principal interests in ACS are the science curriculum, facilities for computing, and laboratories. His original connections to the school came through Dr. Floyd H. Black, whom he met in graduate school and through his father-in-law, who taught English at ACS from 1938 to 1942.

Trayan Trayanov

Trustee since 2017
  • MPhil in Sociology, University of Cambridge

  • AB in Social Studies, Harvard College

  • Program Director, Teach For Bulgaria

Trayan graduated from the American College of Sofia in 2001. Since 2014, he has been helping organize the Student Activities Fund at ACS, which supports extracurricular student projects and initiatives with small grants and mentoring. He previously served on the Alumni Fund Advisory Committee and has been a member of the Planning & Accreditation Committee at ACS.

Roger Whitaker

Trustee since 1990
  • Doctor of Philosophy, Boston University

  • Professor Emeritus, The George Washington University

Dr. Whitaker was the founding President of the College when it reopened in 1992 and has served as Trustee since 1990. He is a former Chair of the Board.

William J. Williams, Jr.

Trustee since 1990
  • BA, College of the Holy Cross, Worcester, MA

  • LLB (Bachelor of Laws), New York University, School of Law

  • Lawyer, Sullivan & Cromwell LLP

The relationship between partners of Sullivan & Cromwell and ACS dates back over 75 years. Mr. Williams has been a lawyer at S&C since 1962, including partner from 1969 to 2004 and Of Counsel since. He is a former Chair of the Board.

David Bliss Wilson

Trustee since 2014
  • Northeastern University School of Law, J.D. (1986)

  • Amherst College, B.A. (1982)

  • Partner specializing in management side employment law and litigation, Hirsch Roberts Weinstein LLP, Boston, MA, USA

Mr. Wilson’s grandfather Howard H. Bliss taught English at ACS in the period 1938-42 and his mother attended ACS in first grade. His uncle Joel Studebaker serves on the ACS Board of Trustees.