Answer:
The Arabian Peninsula is situated between the Arabian Sea (Indian Ocean) and the Mediterrnen Sea. As there was no sea connection, trade routes criss crossed the Peninsula and imporant trding ports sprang up all along the perifery. This was the primary economic activity for centuries, involvement in trade or raiding those involved in trade. With the Islamic outburst, Arabs seized control of a vast empire (7th century).
Hope this helps :D
