People are free to choose what they want but you mainly keep only the "main" surname from each parent. I know in England there was a tendency of people keeping

People are free to choose what they want but you mainly keep only the "main" surname from each parent. I know in England there was a tendency of people keeping both names of powerful families[1][2], then as double-barreled surnames. Which then sometimes went a bit nuts a few generations later if they married into other double-barreled families [3]. I think it was when I visited Stowe School, the seat of the Dukes of Buckingham and looked at the family tree, that I even saw some surnames repeated if they married into other families which shared one of their multi-barreled surnames... [1] https://www.theguardian.com/lifeandstyle/2017/nov/02/keeping-up-with-smith-joneses-no-longer-posh-double-barrelled-surname https://www.theguardian.com/lifeandstyle/2017/nov/02/keeping... [2] https://www.telegraph.co.uk/family/parenting/are-we-heading-for-a-generation-of-kids-with-quadruple-barrelled-names/ https://www.telegraph.co.uk/family/parenting/are-we-heading-... [3] https://en.wikipedia.org/wiki/Richard_Temple-Nugent-Brydges-Chandos-Grenville,_1st_Duke_of_Buckingham_and_Chandos https://en.wikipedia.org/wiki/Richard_Temple-Nugent-Brydges-...