Markus Tollinger was the father of Katie Tollinger.
Biography
He came to Moscow in November 1967 in order to see the Major Maxim Alexandrovitch Felnikov and to take something from the Kremlin. He worked with the Ice Warrior Hhessh to obtain some artefacts, including the helmet of the Ice Lord Sezhyr.
He along with Raina Kerenskaya met up with the Seventh Doctor and Ace, the later of whom discovered Hhessh, the two decided to join him, Hhessh and Major Felnikov on the mission. After learning that Raina was pregnent, he and the others were taken aboard the Ice Warrior ship. He and the Doctor then left with the newborn baby, but later returned to free Raina who had been taken over by Sezhyr. (DW: Ice Time)
Markus later married Raina, but their marriage eventually fell apart. (DW: Crime of the Century)
Twenty-three years after meeting him, Markus was reunited with the Seventh Doctor in 1990. He and Katie eventually patched up their relationship and he helped her and the Doctor get to Kafiristan. (DW: Crime of the Century)
Markus had died by 2001. (DW: Blood and Iron)