Er

The eldest son of Judah by his wife known to us only as "the daughter of a Canaanite man named Shua" (Gen 38:1). Er is notorious for being "wicked in the Lord's sight; so the Lord put him to death" (Gen 38:7). This gives him the dubious honour of being the first named person to be put to death by the Lord.

Two other persons in the Bible are known by this name. 1) "Er the father of Lecah," and son of Shelah (1 Chron 4:21), and 2) "Er, the son of Joshua, the son of Eliezer" (Lk 3:28). Of them we know nothing.