Andreas Tanis

Andreas Tanis is a character in the 2006 movie Underworld: Evolution. He is portrayed by Steven Mackintosh.

As a historian

Tanis is a vampire of considerable age and is the official Coven Historian. However, 300 years prior to the events that occurred within the first Underworld movie, he had been accused of recording "malicious lies" about Viktor, one of the Coven Elders. For his trouble, he was exiled by Selene to an abandoned monastery. 300 years later, Selene would learn the truth about Viktor and realise that what Tanis had recorded years earlier was, in fact, true.

Marcus Corvinus stated that he often enjoyed the company of Tanis. This is most likely because Tanis had discovered the truth and thus knew who the original Vampire was all along: Marcus.

In Exile

Deal with Lucian

During his imprisonment, Tanis established a comfortable life by trading with the Lycans (most specifically Lucian), providing the UV rounds which are fatal to Vampires. In return, he received Lycan Bodyguards (whom Michael and Selene fought and killed), and also wine, women and other comforts — making his exile quite pleasant (and causing Selene to jeer, "Your exile seems more comfortable than I remember").

Evolution

Reveals the truth to Selene

It is through Tanis that Selene comes to realize her great importance and why she's valuable to Marcus — after William was captured, it was Selene's father who built his prison, and following the deaths of her entire family she was the only one who knew its location. She also holds half of the key to William's cell, which had been passed from Sonja to Lucian, and which she had also seen in her childhood but forgotten. Tanis informs both Michael and Selene about Marcus' history, and that of his brother William. He also arranges for Selene and Michael to visit Alexander Corvinus in exchange for Selene's "discretion," which she reluctantly provides.

Death

Marcus, who was looking for both of the keys to William's prison, arrived and interrogated Tanis. Frustrated with Tanis' lack of answers, Marcus then bit him acquiring his memories through his blood, including those of his conversations with Selene and Michael.