Jose Cayetano Lopez de Jaen was born circa 1747, the son of Miguel Lopez de Jaen and Maria Gertrudis Longoria.
He married Maria Antonia Gonzalez on 18 Feb 1775 in Mier.
In 1782, he lived at El Cojo. The church census recorded that he was married, español, and 34 years old. His household included 6 people:
Jose Cayetano Lopez de Jaen, español, married, age 34.
Maria Antonia Gonzalez, española, married, age 26.
Juana Maria Lopez, española, a young child, age 4.
Maria Gertrudis Lopez, española, a young child, age 3.
Jose Rafael Lopez, español, a young child, age 2.
Juan Antonio Santos, español, a youth, age 15.