Often called Suruga Dainagon (the major counsellor of Suruga), Tadanaga was born in 1606. The date of his birth is uncertain, and is variously given as May 7, June 1, and December 3. As a youth, he received support from his mother, Oeyo (or Sūgen'in), who favored him over her other son Iemitsu to become the third shogun. Later, his misconduct resulted in his being stripped of office, and he committed seppuku.
Tokugawa Tadanaga was missing on the "original" date of his forced suicide. It was suspected that he had heard of his historical death from up-time source and fled or was simply executed "early" by his brother Tokugawa Iemitsu.
The mention of this was edited out of 1636: The Kremlin Games. It can be assumed that Tadanaga was still missing on the "original" date of his forced suicide.