The new law officially makes 18 the minimum age for marriage. Previously, 16-year-olds were allowed to marry adults in certain cases with court permission.
The legislation also nullifies any existing marriages in which at least one spouse was under the age of 16 at the time of the wedding. This is particularly aimed at marriages done outside of Germany.
Read more here: https://www.thelocal.de/20170602/german-parliament-passes-law-ending-child-marriage