===== Marriage certificates =====
The marriage certificate contains information about the bride and groom, their name, age and town of origin. It also contains information about the parents. Most importantly, it either gives their residence or locates their death.
Tips: If a parent is still alive, they are likely to die in the following decade. Hence, you can often use this information to find the death certificate . A couple often married in the town where the wife was living. If you know where she was born, check there.
If you are lucky, the parents married in the same village as their child was born. The marriage certificate contains information about the bride and groom, but also about their parents. Most importantly, it locates their death or, if they are still alive, it gives the residence. In the later case, they are likely do die within the following decade in that village. Either way, you can easily find their death certificate. The death certificate contains the age, town of origin and the name of the parents, which makes it possible to find the birth certificate.
A more secure approach is to search for the marriage certificate of the ancestors for whom you already have the birth certificate. They likely married in the birth town of the wife. The marriage certificate helps to locate the death certificate of the parents, which helps to locate their birth certificate. It is also possible to search for the death certificate directly, but then you might have to search through multiple decades. You can also search for the birth certificates of the sibling. This can help estimate the marriage and death dates of the parents.
=== Belgium Research Strategies ===