Pedro started in the world of image in a self-taught way in the late 80's, to be academically trained at the Escuela Superior de Comunicación, Imagen y Sonido (1990-1992). He began his professional career in the laboratory of the Europa Press Agency to continue in the Cover Agency, Diario El Mundo, Interviú magazine and collaborations for various national and international media. Between 2003 and mid-2016 he distributes his images through the International agency France Presse. 

Since his professional beginnings he maintains a close relationship with different Organizations for whom he does documentation work, destined to media, exhibitions, technical reports, etc.

Founding partner with journalist Susana Hidalgo of the digital magazine Calamar2 specialized in social and environmental issues, and in the production of multimedia content for television and other media. Development and elaboration of technical research for organizations and entities of different types.

In March 2015 creates www.armestregallery.com. Online gallery where you can purchase copies of author in Limited Series.

Included in 2013 in Fujifilm's X-Photographers as brand ambassador.

Highlight publications worldwide thanks to AFP agency and other distribution channels.