John Emerich Edward Dalberg-Acton, 1st Baron Acton, 13th Marquess of Groppoli,, better known as Lord Acton, was an English Catholic historian, politician, and writer. He is best remembered for the remark he wrote in a letter to an Anglican bishop in 1887: "Power tends to corrupt, and absolute power corrupts absolutely."

Sir John Francis Edward Acton, 6th Baronet was a French-born English gentleman who served as Commander of the naval forces of the Grand Duchy of Tuscany and later as Prime Minister of the Kingdom of Naples under Ferdinand IV. He served at Naples during the turbulent times when French Revolutionary fervour under Napoleon was sweeping across Europe and threatening to extinguish the monarchy he served.