Pedzisa mutsara unotevera: Akakunda muna 1347, John VI Kantakouzenos akatonga samambo pamwe chete kusvikira mwanakomana wake Matthew Kantakouzenos arwiswa naJohn V muna 1352, zvichitungamirira ku
hondo yevagari vemo yechipiri. John V akakumbira mutongi weSerbia, Stefan Dušan kuti amubatsire, uye Dušan akazvipira nokutumira vatasvi vemabhiza vechiSerbia 4 000 kuti vamubatsire. Matthew Kantakouzenos akakumbira baba vake rubatsiro, uye maOttoman maTurkey zviuru gumi vakaratidza paDemotika (Didymoteicho) muna Gumiguru 1352 uye vakarwa nemauto evaSerbia vaJohn V muhondo yakavhurika yemunda iyo yakaguma nekuparadzwa kwevabatsiri uye kukunda kwevaTurkey vakawanda vari mubasa reByzantine. Umambo hweOttoman nokudaro hwakawana nharaunda yahwo yokutanga yeEurope, paÇimpe neGallipoli. Akakwanisa kutorazve Constantinople muna 1354, John V akabvisa uye akacheka John VI Kantakouzenos; na1357, akanga abvisawo Matthew, uyo akanga abatwa nemaSerbia uye akabhadharwa naJohn V.