Question: When did Isabella Of Portugal, Duchess Of Burgundy's mother die?
Sentence (from "Philippa of Lancaster"): Philippa of Lancaster (31 March 1360 – 19 July 1415) was Queen of Portugal from 1387 until 1415 by marriage to King John I. Born into the royal family of England, her marriage secured the Treaty of Windsor and produced several children who became known as the "Illustrious Generation" in Portugal.
Relevant evidence: Yes