Board Thread:Support Requests - Designing Your Wiki/@comment-39464250-20200810203218/@comment-45117243-20200810211654

For the Gentim Book Basic font, put this code at the very beginning of your wiki MediaWiki:wikia.css page:

@import url('https://fonts.googleapis.com/css2?family=Gentium+Book+Basic&display=swap');

The other fonts you are mentioned, as well as the Palatino fonts, seem to not be free, but maybe someone else here knows better. There are other free Caslon fonts here.