Complex sentence: After Vasco's death, Graves and Augustus agreed to sit down with the remaining members of the Trust where, as part of a peace agreement brokered by Augustus, Graves was forced to resign as Agent, only to assume rule over the vacant House of Vasco.
Split into simpler sentences: After Vasco's death, Graves and Augustus agreed to sit down with the remaining members of the Trust. As part of the Trust's peace agreement, Graves was forced to resign as Agent and take over the vacant House of Vasco.