Randolph Wright

 was Polly's patrilineal uncle. A pilot shot down over France, he died in a Nazi prisoner of war camp during World War II. He was survived by his two older brothers, including Polly's father, Edward. The older Wright honoured his younger brother's memory by telling Polly tales of her uncle after the war.

In February, 1944, Polly met a man whom she thought was her uncle, but he turned out to be a Nazi agent who had tried to impresonate Randolph for the purposes of infiltrating the French resistance. (CC: Resistance)
 * That Randolph's surname is mentioned in Resistance is significant. Polly's surname, by contrast, was never mentioned in any bit of performed Doctor Who up to this point. "Wright" had instead derived from the Gary Russell book, Invasion of the Cat-People.  The explicit mention of his last name in a piece of performed Doctor Who'' thus gives the name "Polly Wright" a measure of wider acceptance and therefore greater authority.