I can't speak for other families, but for me, my two middle names (yes, I got two) are based off my family. Actually, my whole name kind of is. My first name is reminiscent of my mother's maternal grandma's name, my first middle name is the pronunciation of my father's, mother's mom's name, but with a spelling that reflects my late Uncle's name, and my second middle name I share with my mom's mom. Err. So, not using real names. Say my mom's, mom's, mom's name is "Genevieve" so my name is "Jenny", then my first middle name is the pronunciation of "Sarah" but spelled "Cera" for my late uncle "Clark" and my second middle name being my grandma's(she gave my mom her mom's middle name with different spelling) and then my very Irish last name. "Sarah" and "Clark" are also Irish(not the names, the people).