Rubén Darío explained it as follows in his autobiography: According to what some of the old people in that town of my childhood have referred to me, my great-grandfather had Darío as his nickname or first name.
O propio Rubén o explica na súa autobiografía: Segundo o que algúns anciáns daquela cidade da miña nenez me referiron, un meu tataravó tiña por nome Darío.