Complex sentence: He was married to Angélica Andrade, daughter of landowners, and descendant of Casimiro Alegre and Francisco Monterroso, (born c.1760 in Puerto de Santa María) the gunsmith to the Regiment Cantabros Montañeses.
Split into simpler sentences: He was married to Angélica Andrade, daughter of landowners, and descendant of Casimiro Alegre. And of Francisco Monterroso, (born c.1760 in Puerto de Santa María) the gunsmith to the Regiment Cantabros Montañeses.