You need to bring an original birth certificate with you the Netherlands. But then we’re not quite there yet, because this one needs to be officially legislated by an apostille seal. And afterwards, you also need to have this translated to English.
If you are married, same exact thing with your marriage certificate. And your partner also needs to get this birth certificate.
Do you have kids? Great! But you need to follow the same process for their birth certificates.
Are you in a permanent relationship, but not officially married? No problem. But then no marriage certificate off course. In this case you need to fill out a bunch of additional documents from the IND in which you basically provide proof of your relationship.
But next to this, you also need to get certificates that state that the both of you are not officially married. And these also need to be in your native language, with apostille seal and also translated to English.