Complex sentence: They have started buying lands in Mount-Lebanon during the 1100 era and more specifically first in "Jaj" currently under Jbeil district then continued their exodus to the Keserwan district where they have baught lands from the Chi'a Tribes.
Split into simpler sentences: They have started buying and acquiring lands in Mount-Lebanon during the 1100 era and more specifically first in "Jaj" currently under Jbeil district. Then continued their exodus to the Keserwan district where they have baught lands from the Chi'a Tribes.