Meet The  AUTHOR.

Guy R. Powell is an author, historian, and researcher focused on the Shroud of Turin, one of the most studied and debated artifacts in history. Through his writing, speaking, and media platforms, he explores the historical, scientific, and theological dimensions of the Shroud, helping audiences better understand its significance and enduring mystery. 

He is the author of The Only Witness, a historical exploration of the Shroud of Turin that brings together centuries of research, narrative storytelling, and historical context. Guy also hosts The Backstory on the Shroud of Turin (https://www.youtube.com/@Guy.R.Powell.ShroudofTurin), where he interviews leading scholars, researchers, and experts to uncover new insights into the Shroud’s origins, authenticity, and meaning.

Guy is actively involved in advancing Shroud research and education, serving on the boards of Othonia (https://othonia.com), STERA (https://www.shroud.com), and SEEC (https://shroud2025conference.com/). His work contributes to ongoing global efforts to study, preserve, and communicate the importance of the Shroud to both academic and public audiences.

In addition to his historical work, Guy brings more than 20 years of experience as a marketing strategist, analytics expert, and author. As the founder of ProRelevant (https://prorelevant.com), he has helped organizations across industries and global markets understand what drives growth through marketing ROI, marketing mix modeling, prescriptive analytics, and AI-driven market research. Guy has also been interviewed on television with Atlanta News First (https://www.youtube.com/watch?v=3R0uzlo6ODM)

He is also the author of multiple books on marketing and analytics, including Marketing Calculator, The ROI of Social Media, The Marketing Machine, The Post-Covid Marketing Machine, and The AI Marketing Machine, and hosts The Backstory on Marketing and AI (https://www.youtube.com/@BackstoryOnMarketingandAI), featuring conversations with leading marketers shaping the future of the industry.