According to Wikipedia, a posthumous birth is a “birth of a child after the death of a biological parent.” For obvious reasons, it is much more common that a father died before the birth of a child. In a rare occasion the death involved the mother. Today, we are looking at the posthumous birth of Harmen Boelens (1578).
On the 2nd of November  is baptized the child of Boele Harmen’s widow, born after the death of the husband, being a son named Harmen.
We gave a different example of an entry in a baptismal register in one of our previous articles. This is of course a very remarkable one, where the father died prior to the baptism. In Dutch we speak of a postuum geboren kind.
Under current Dutch law children who are born within 306 days after the death of the father are still considered to be of the deceased man. [source: Rijksoverheid] A similar rule applied in the 17th century. The famous Dutch lawyer Hugo de Groot wrote in 1631 his book Inleydinge tot de Hollantsche rechtsgeleertheit [The introduction to Dutch jurisprudence]. He said that children of a married woman were considered to be legitimate children of her husband. He named two exceptions: “unless there be manifest proof of his incompetency to beget children, or of absence inconsistent with the time of pregnancy; the period being limited to seven months at the least, and to eleven months at the utmost.” [source: pages 50-51 of the English version, HathiTrust Digital Library]
We do not know when Boele Harmens died. Parish registers from the 1560/70s are rare in the Netherlands. We are lucky that this one still exists for Sneek. There is no such register of deaths or burials. Without additional information we cannot be certain whether Harmen was a legitimate son of Boele Harmens.
Can we just assume he was a son of Boele, as he was named after his paternal grandfather. To be honest, are we really sure he was named after him? We do not know the name of Harmen’s mother. As a result, we do not know the name of his maternal grandfather. What if both his grandfathers were a Harmen?
Perhaps other documents – for example notarial records or records of the schepenbank, the college of aldermen that served as a local court – might shed new light on the death of Boele Harmens, his marriage and his offspring.
On the list of posthumously born notable persons are many royals. For example Alexander, the son of Alexander the Great. His father died in 323BC, two months before the birth. The English king Henry VII was born in 1457, three months after the death of his father Edmund Tudor.
Mary Stuart gave birth to the future king of England, William of Orange in 1650. His father, who was stadtholder of several Dutch provinces, died eight days before the birth. William of Orange’s heir in the Netherlands was John William Friso (Johan Willem Friso), who drowned in 1711. His son, stadtholder William IV, came into the world six weeks after the accident.
Examples of posthumously born presidents of the United States are: Andrew Jackson (1767), Rutherford B. Hayes (1822) and Bill Clinton (1946).
These examples show that posthumous births occur more often than one might think. Perhaps one of your ancestors died before the birth of his child. Of course you do not want to miss a child! We therefore recommend that you always check (an index for) births and baptisms for an extra period of one year, to rule out the possibility of a posthumously born child.