Diederick Slijkerman (PhD, LLM) is researcher at the Institute for History of the University of Leiden, the Netherlands. He studied both Law and History at Leiden University and afterwards Theology at the University of Utrecht. At the University of Leiden he took his PhD in a study about the relationship between crown, cabinet, Commons and constituencies development of ministerial responsibility in the 19th and 20th century. He specialized in (European) political history. Recently, he published a book about Wim Treub, a Dutch politician at the end of the 19th and the first quarter of the 20th century (Bert Bakker/Prometheus, Amsterdam) and “Ministerial Responsibility as a Safety Valve for the Constitutional Powers in Great Britain from the Seventeenth Century Onwards” in: Journal of Constitutional History 1 (2016) 223-249.