Ad van Liempt joined De Telegraaf, one of the largest Dutch newspapers, where he continues to contribute his expertise in historical journalism. His role at De Telegraaf involves writing columns and articles that draw on his extensive knowledge of Dutch history, particularly World War II.

Ad van Liempt published 'Selma', a poignant biography of Selma Wijnberg, a Dutch Holocaust survivor. The book received critical acclaim for its sensitive portrayal of Wijnberg's experiences and van Liempt's meticulous research, showcasing his ability to handle delicate historical subjects with care and insight.

Ad van Liempt was awarded the Ereteken voor Verdienste, a prestigious Dutch honor recognizing his outstanding contributions to journalism and historical research. This accolade highlighted his influence in the field and his dedication to uncovering and presenting historical truths.

In 2007, Ad van Liempt published 'De Oorlog', a comprehensive book that accompanied a television series on World War II. The book and series were praised for their detailed research and engaging presentation, further cementing van Liempt's reputation as a leading historian and journalist in the Netherlands.

Ad van Liempt was instrumental in launching 'Andere Tijden', a historical television program on the Dutch public broadcaster. The show focused on significant historical events and figures, offering viewers a deep dive into the past. It became a staple of Dutch television and demonstrated van Liempt's expertise in historical storytelling.

Ad van Liempt published 'Kopgeld', a groundbreaking book that delved into the controversial topic of Dutch bounty hunters during World War II. The book was well-received for its thorough research and compelling narrative, establishing van Liempt as a leading figure in historical journalism.

Ad van Liempt joined the NOS, the Dutch public broadcasting organization, where he worked as an editor and later as a program maker. His tenure at NOS marked a significant period in his career, allowing him to explore television journalism and produce impactful historical documentaries.

Ad van Liempt began his journalism career at Het Vrije Volk, a Dutch newspaper known for its progressive stance. During his time there, he honed his skills in reporting and developed a keen interest in historical journalism, setting the foundation for his future work.