Complex sentence: The other de Totnes sister, whose name is unknown, married Henry de Tracy (d.pre-1165), leaving a son and heir Oliver de Tracy (d.circa 1184), who in 1165 was charged scutage on 25 knights' fees for his moiety.
Split into simpler sentences: The other de Totnes sister, whose name is unknown, married Henry de Tracy (d.pre-1165), leaving a son and heir Oliver de Tracy (d.circa 1184). In 1165 Oliver de Tracy was charged scutage on 25 knights' fees for his moiety.