Estate of a Convert
A Jew whose Jewish ancestry goes back many generations can never die without heirs. The reason is that when there are no children the chain of inheritance goes upwards to the parents or grandparents, all the way back to the patriarch Yaakov. Even if the parents or grandparents and so on have already passed away, the estate just returns back downwards to the children or grandchildren of these "virtual" heirs, so that the estate will go to the first, second, or third cousins or even farther, until eligible heirs are found from among the entire Jewish people (SA CM 276:1)
However, a convert who dies without children has no heirs. The chain of inheritance goes back to Yaakov, not to Avraham who is the father of converts. The result is that the estate of a childless convert in Jewish law is considered ownerless property, exactly as if the convert had explicitly renounced ownership. Indeed, the Rambam states explicitly "The possessions of a convert who has no heirs and possessions which have been renounced... have the identical status" (Zechia umatana 2:1, SA CM 275:12).
The simplest understanding of this situation is that it is the result of some unfortunate discrepancy. While someone's estate is normally supposed to be bequeathed to heirs, the unfortunate convert somehow slips between the cracks and so by mere default the property becomes ownerless. However, Rav Natan of Breslav provides a profound interpretation of this law which practically reverses this understanding.
Rav Natan explains that normally when a Jew passes away, his possessions pass in a well-defined way to specific heirs; other members of the Jewish people are excluded.
However, a convert has a special status. He (or she) has a much more general soul. While a born Jew traces his ancestry to his or her specific father and mother, the convert is the child of Avraham and Sarah, the founders of the Jewish people and of the pure worship of HaShem. Rav Natan goes beyond this and states that converts are also the spiritual progeny of the especially righteous: "the main progeny of the righteous is the souls of the converts." Likewise, when we trace our family tree forward the usual situation is that there are specific heirs, but in the case of a childless convert "the estate of a convert belongs to the entire Jewish people."
In other words, we don't have a negative, default situation where the property belongs to no one, but on the contrary a remarkable positive condition where the property passes to the everyone. "For in principle the soul of the convert is drawn from the entire community of Israel."
According to this explanation, the law regarding the estate of a convert bears a remarkable insight. Just as the seemingly parentless convert is not bereft of parents but on the contrary is the offspring of Avraham and Sarah, who constitute the root of the entire Jewish people, so the seemingly childless convert is not truly bereft of children but on the contrary the entire Jewish people are like his offspring, and are entitled to a share in his estate. - (Likutei Halakhot Breslav Hefker 2)
[NOTE: This analysis seems to imply that the estate of a convert is intended primarily for Jews. I have found no explicit source for such a distinction, but it is plausible for the following reason: The rules of this type of ownerless property are derived from the rules of the Sabbatical year (Yerushalmi Peah 6:1, mentioned in Tosafot BK 28a). And the ownerless produce of the Shmita year is intended primarily for Jews (Rambam Shemitta 4:30, Sifra on Vayikra 25:6). If any reader knows of a source which explicitly supports or refutes this idea, I would appreciate a reference. Another possibility is that the convert is considered a patriarch for all humanity, exactly like Avraham whose name means "father of a multitude of nations" (Bereshit 17:5). -AM]