Complex sentence: He is also noted as the founder of the "Itto Shoden Muto-ryu" school of swordsmanship, which in time gave birth to the modern Japanese style of swordsmanship or Kendo.
Split into simpler sentences: He is also noted as the founder of the "Itto Shoden Muto-ryu" school of swordsmanship. Which in time gave birth to the modern Japanese style of swordmanship or Kendo.