Alex was a cyborg heir to the Robotov Empire who had a Skishtari gene egg implanted in him as a child. The egg was removed when he was still a toddler, by the Fourth Doctor.

By wormhole, Alex ended up in 19th century Hexford, where he began to be known as Andrew and beceame the ward of Dobbs. He liked to explore the village of Hexford after dark. He wore a mask to hide his true appearance. He was in fact the heir of the Robotov Empire. (AUDIO: The Broken Crown)

When he went into the land inside the special Skishtari egg he owned, he believed he was Aladdin. In this guise, he travelled to find the magic lamp. (AUDIO: Aladdin Time)

After The Doctor returned him to the Robotov Empire, he became the Tsar. Because of his connection to the Skishtari egg, he stopped Lucius' plans to use the creature inside to take over the Robotov Empire. (AUDIO: Survivors in Space)