The Martens Clause owes its name to the diplomat and jurist Fyodor Fyodorovich Martens, a representative of the Russian Empire at the First Hague Conference in 1899. Drafted and proposed by Martens during the negotiations, yet as a spontaneous compromise, the Clause has been included in the preamble of the Hague Convention with Respect to the Laws and Customs of War on Land and is still considered an important principle of international humanitarian law today. This article traces the biography and academic path of F. F. Martens and explores the enduring significance of the Martens Clause.