http://www.expatica.com/source/site_article.asp?subchannel_id=24&story_id=25996
"The federal government is to tighten family migration regulations by sharpening the pre-conditions applied before foreign partners are allowed to enter Belgium. A spokesman for Interior Minister Patrick Dewael said on Thursday the minimum age requirement will be lifted from 18 to 21. This will apply to both the Belgian resident and their foreign partner."
