Constantine has spent the past ten years documenting stateless communities from Bangladesh, Myanmar, Nepal, Malaysia, Sri Lanka, Kenya, Ivory Coast, Dominican Republic, Ukraine, Serbia, Italy, Iraq, Kuwait and Lebanon. He began his work on the Rohingya in early 2006. From 2006-2012, he traveled eight times to southern Bangladesh for his work on the Rohingya and he has traveled four times inside Burma since ethnic violence broke out in June 2012. Published in mid-2012, his book, Exiled To Nowhere: Burma’s Rohingya was named a 2012 Notable Photo Book of the Year by the Independent on Sunday in the UK and PDN Magazine in the US and was named a finalist for the2013 IPA Photo Book Asia Award. Since the publication of the book and the outbreak of violence against the Rohingya inside Burma, Constantine has continued his long-term documentation of abuse toward the Rohingya community.
His work has been recognized in Pictures of the Year International, NPPA Best of Photojournalism, the Human Rights Press Awards (Hong Kong), the Society of Publishers in Asia, Days Japan, Allard Prize for Photography, International Photography Awards, Prix de la Photographie and the Harry Chapin Media Award for Photojournalism. Constantine was part of a team of journalists from the International Herald Tribune who received the Osborn Elliot Prize for Journalism in Asia in 2009, presented annually by the Asia Society. In 2011, he was shortlisted for the Amnesty International Media Award for Photojournalism in the UK. He is a recipient of an Audience Engagement Grant from the Open Society Institute (OSI) and was also selected by the Documentary Photography Project at OSI for the prestigious group exhibition, Moving Walls 19. He is a two-time grant recipient of the Pulitzer Center on Crisis Reporting and has also received grants from the National Endowment for Democracy and the Oak Foundation. Since 2006, his project on statelessness has also been supported through the non-profit fiscal sponsorship of Blue Earth Alliance.
He has collaborated and has been commissioned to work on projects with international organizations such as: Human Rights Watch, Amnesty International, Refugees International, Medecins Sans Frontieres, UNHCR, World Food Program and the Open Society Foundations,
A series of inter-related books from the project Nowhere People was launched in 2011. The first book in the series was Kenya’s Nubians: Then & Now. The second in the series was Exiled To Nowhere: Burma’s Rohingyawhich was named a 2012 Notable Photo Book of the Year by the Independent on Sunday in the UK and PDN Magazine in the US and was named a finalist for the 2013 IPA Photo Book Asia Award. The third book in the series, Nowhere People was released in early November 2015. In addition, an eBook, In Seach of Home, was published by the Pulitzer Center on Crisis Reporting. Exhibitions of his work related to global statelessness have been shown in: Royal Albert Hall and HOST Gallery in London, BBVA Bank Gallery in Madrid, Palace of Fine Arts in Budapest, Department of Justice in Dublin, Palais des Nations and Plaine de Plainpalais in Geneva, European Parliament in Brussels, Philippines Cultural Centre in Manila, Go Down Arts Centre in Nairobi, The Kennedy Center and US Holocaust Museum in Washington DC, at the UN Headquarters and powerHouse Arena in NYC and at the Peace Palace in The Hague during the 1st Global Forum on Statelessness held in 2014.
In 2015, he was a Distinguished Visiting Fellow at Queen Mary University of London in collaboration with the State Crime Initiative. He is currently based in SE Asia.