The National University of San Marcos (Spanish: Universidad Nacional Mayor de San Marcos, UNMSM) is the most important and respected higher-education institution in Peru. It consistently ranks among the top two universities in the country San Marcos was officially established by a royal decree (signed by Charles V, Holy Roman Emperor) on May 12, 1551, and since then it has operated without interruption. Hence, it is known as the Dean of America ("dean" in the sense of "oldest member"). San Marcos also claims that according to the Archivo General de Indias, a famous Spanish repository of documents on the former colonies in the sixteenth to eighteenth centuries, there were no official records authorizing any other university or higher-education institution before 1551.The Royal and Pontifical University of Mexico was chartered the same year as San Marcos (by a royal decree of September 21, 1551) as the Royal University of Mexico, making it the second oldest in the Americas.