Cervantes was born in Alcalá de Henares, a university town just east of Madrid. Birth records were not ordinarily kept at the time; baptismal records were scrupulously maintained, however. Since he received the name Miguel (Michael) at his christening on 9 October 1547, it is reasonable to assume that he was born on St. Michael’s Day, 29 September, ten days prior. He was the third child of Rodrigo de Cervantes and Leonor de Cortinas. His full name would ordinarily have been, therefore, Miguel de Cervantes Cortinas. Following his captivity in Algiers, and for reasons unknown, he took on the second surname of Saavedra – perhaps an example of Renaissance self-fashioning. One modern-day opinion is that this surname was that …
Parr, James A.. "Miguel de Cervantes". The Literary Encyclopedia. First published 24 October 2008; last revised 30 November -1.
[http://www.litencyc.com/php/speople.php?rec=true&UID=806, accessed 19 April 2015.]