Matsudaira Tadatoshi (松平忠俊)
He was the eldest son of Tadaharu MATSUDAIRA of the Fujii-Matsudaira family. His mother, a daughter of Nagafusa SUGIHARA (an adopted daughter of Nagaakira ASANO), was a lawful wife. His official court rank was Jugoinoge (Junior Fifth Rank, Lower Grade), Gyobu no sho (Junior Assistant Minister of Justice).
He was born as a legitimate child of Tadaharu MATSUDAIRA. In 1636, he met Iemitsu TOKUGAWA and was comfirmed as the successor of the family, however he died at an early age in 1645. Instead of him, his cousin Tadahide MATSUDAIRA from the head family of Fujii-Matsudaira, the family of Yamashiro no kami (Governor of Yamashiro Province), was asked to be adopted as a successor (the heir of the Kameyama Domain).
However, as Tadatoshi's younger paternal half-brother was born, Tadahide was sent back to his parents' home later.