Siege of the Hexion Gates

The Siege of the Hexion Gates took place circa the 25th century. The siege saw the Sontaran Empire clash with the Earth Empire.

Henry Whittington Smythe was heavily involved in the siege. He remembered often being left to "man the fort". In one instance, he was among a hundred people aboard a B-Class Destroyer which came under attack, riddled with holes and running out of oxygen. The Sontarans boarded and demanded the crew surrender. However, Smythe learned about the Sontaran's weak point in their probic vent at the back of their necks and used this discovery to escape and fight back.

In his old age, during the early 26th century, having become a Field Marshal but telling everyone he was a Major, Smythe encountered the Sontarans again when their war against the Rutans reached Chelsea 426. His experience fighting Sontarans during the siege proved useful while assisting the Tenth Doctor.

However, Smyth was killed by a Rutan during the incident. His body was returned to Earth to receive a full military funeral, where he was recognised for his action during the siege, as well as the Martian Wars and the Battle of Mercutio 14. (PROSE: The Taking of Chelsea 426)