The Secretary-General of the Gulf Cooperation Council (GCC), Abdulrahman bin Hamad Al-Atiyyah congratulated the Custodian of the Two Holy Mosques, King Abdullah bin Abdulaziz on the occasion of the National Day and the 78th anniversary for the Unification of the Kingdom of Saudi Arabia by the founder King Abdulaziz bin Abdulrahman Al-Saud. He said this occasion is an historic event, reflecting a clear indication of the Kingdom's achievements made in various fields and its comprehensive development at all levels.