To earn the First Born Child achievement you’ll first need to find a Marriage partner. You can choose from most members of any faction, but you’ll first need to win their affection by speaking with them and visiting them regularly. There are many different ways of doing this, as described in more detail on our marriage page linked above. You should take care in deciding who you want to propose marriage with, since your choice will influence the political options that you’ll have later.

Once you’ve wont he affection of a potential marriage partner, you will often need to gain the approval of their faction leader before the marriage can go ahead. They may ask you to do certain favors for them, but in most cases all you need to do is provide enough material wealth for them to approve. This can come in the form of specific goods, or just a lump sum of denars. This part is generally easier than winning the affection of a potential partner, and once done the ceremony can go ahead! Now all that remains is for you to wait until a child is born…