After receiving a Master of Fine Arts at the London College of Communications in 2005, Brennan’s work has been exhibited in galleries internationally including New York, Mexico City, La Paz, Bolivia and London. His work has appeared in numerous publications including The New York Times, Time Magazine, Amnesty International, ZEKE magazine, and the BBC. A resident of Mexico since 2010, his primary focus is on documenting the rise of social movements and the processes of territory defense in rural and indigenous regions of Latin America. His work on indigenous groups in resistance in Mexico was awarded first place in the 2017 Pictures of the Year International POYI community Awareness Competition. The project is currently sponsored by the Blue Earth Alliance, and received the spring 2018 Documentary Project Fund.