After his election to prime minister, Winston Churchill visited Brak, and asked him to built him weapons to defeat his enemies. Brak agreed, and proceeded to build weapons from blue cobalt.
Brak watched over the ages as his weapons were used in humanity's conflicts over the course of the 20th century, including conflicts such as the Gulf War.
Brak was then visited by Alice Wells, who came on behalf of UNIT to persuade Brak to testify over the creation of blue cobalt weapons. He was killed by a fellow Sontaran who had hunted for Brak ever since his disappearance.
At the time of his death, Brak was known to be the longest-lived Sontaran in history, with a lifespan of over eighty years. (AUDIO: Old Soldiers)