The Rasulid state nurtured Yemen's commercial links with India and the Far East. They profited greatly by the Red Sea transit trade via Aden and Zabid. The economy also boomed due to the agricultural development programs instituted by the kings who promoted massive cultivation of palms. The Rasulid kings enjoyed the support of the population of Tihama and southern Yemen, while they had to buy the loyalty of Yemen's restive northern highland tribes.