Charles Frederick Henningsen (1815 – 14 June 1877) was a writer, mercenary, filibuster, and munitions expert. He participated in civil wars and independence movements in Spain, Nicaragua, Hungary, and the United States. He was born either in Brussels or in England of Swedish ancestry. One of his sisters was Josephine Amelie de Henningsen, who later became a member of the Missionary Sisters of the Assumption, who established the order in South Africa in 1849.
He fought in the First Carlist War, after entering as a volunteer in the service of Don Carlos in 1834. Henningsen rose to be captain of bodyguard to the Carlist general Tomás de Zumalacárregui. After the signing of the Lord Eliot Convention in April 1835, at which he was present, Henningsen returned to England.
However, Henningsen soon returned to Spain with the rank of lieutenant-colonel and joined the Carlist expedition that threatened Madrid from Aragon.
He fought at the Battle of Villar de los Navarros (24 August 1837), a Carlist victory, earning the rank of colonel. He headed the Carlist lancers and was attacked outside of Madrid by Liberal (Isabeline) forces. He led a column against these forces, capturing the outer fortifications of Madrid. He held them for several hours, until notified that Don Carlos could send him no reinforcements.
However, he was subsequently taken prisoner, and released on parole. He did not serve again in this war. He later recorded his experiences in Spain in the book The Most Striking Events of a Twelvemonth's Campaign with Zumalacarregui, which he dedicated to Lord Eliot. The work created controversy in Britain because it glorified Zumalacárregui and supported the Carlist position.