His real name was said to have been Shimura, because Takenori's mother remarried into the powerful Shimura clan after his elder brother Tomomasa was born, and subsequently Takenori was born.
本姓は志村だったとされている（武則の母が兄朝正を産んだ後、豪族志村氏と再婚し、その際に産まれたのが武則である為。）。