Edward Woodbourne

 was a soldier who fought in World War I. His wife was named Mary and he had a son named Joshua.

In the trenches on Christmas Day in 1914, Edward met the Fifth Doctor, who had become separated from his friend. They talked, and he told the Doctor he would like to travel. Later, he wrote a letter to his wife.

Edward was killed in the fighting. The Seventh Doctor obtained the letter and delivered it to Mary. (PROSE: Never Seen Cairo)