Are these sentences worded properly?

FYI- Grigor is the harmach. Upon Geran’s return to his birthplace, he quickly learned about the many considerable changes that had occurred in Hulburg since his departure. Several years earlier, Kara’s ambitious stepbrother, Sergen, had convinced Grigor to sell out trade concessions for logging and mining in the Hulmaster lands since demands were very high in the nearby Moonsea cities. The powerful House Veruna of Mulmaster, House Jannarsk of Phlan, and the other merchant companies that moved into Hulburg formed a Merchant Council, and Sergen was named the harmach’s representative on the new committee.