Mstislav Rostislavich
In 1172 and 1173 , Mstislav also helped his brothers , Roman Rostislavich and then Rurik , take the throne in Kiev ( indeed , Riurik sat on the Kievan throne seven times ) . 
<triplet> Roman Rostislavich <subj> Rurik <obj> sibling <triplet> Rurik <subj> Roman Rostislavich <obj> sibling