Legal Definitions - eisne

Historically, the term eisne referred to someone who was the eldest or firstborn.

A more specific and legally significant historical term was bastard eisne. This described an illegitimate son who was the firstborn child of his parents. This status became particularly relevant if his parents later married each other and subsequently had another son. Under historical common law, especially in England, the "bastard eisne" was generally not considered a legitimate heir for purposes of inheriting titles or land, even if his parents eventually married. The later-born son, born after the parents' marriage, would be considered the legitimate heir.

• Example 1: Inheritance of a Feudal Estate

  Imagine a scenario in 15th-century France where a local lord, Baron Dubois, had a son named Henri with a woman named Marie. A few years later, Baron Dubois and Marie officially married and subsequently had another son, Louis. Henri, being the firstborn son but born before his parents' marriage, would be considered the bastard eisne. Despite his parents' later marriage, under the prevailing legal customs of the time, Henri would typically not be eligible to inherit his father's title or lands. Instead, the legitimate second son, Louis, would be recognized as the rightful heir.

  This example illustrates how the status of bastard eisne, even with the parents' eventual marriage, historically prevented the firstborn from inheriting significant property or titles due to the circumstances of their birth.

• Example 2: Succession in a Landed Family

  Consider a wealthy English family in the 17th century, the Wellingtons, who owned a substantial country estate. The eldest son, Edward, was born to Mr. and Mrs. Wellington before their formal marriage. Several years later, after they were legally married, they had a second son, George. Edward would be classified as the bastard eisne. According to English common law at the time, even though his parents married after his birth, Edward would not be considered a legitimate heir to the family estate. The inheritance would instead pass to George, the younger son born within the bounds of legal marriage.

  This scenario demonstrates that the legal distinction of bastard eisne was crucial for determining succession to family property, prioritizing legitimacy of birth over the simple order of birth, even if the parents later married.