of South Korea in the years before the war, the North Korean leadership began to create large numbers of commando and special forces units to send south. These units subverted South Korean authority before and during the war with terror campaigns, sabotage and inducing rebellions in ROK military units. Hundreds of commandos were sent to South Korea in this fashion, and by the end of the war up to 3,000 of them had been trained and armed. During this time, North Korean leadership also ordered the creation of large conventional units to act as advance forces for the actual invasion. The 766th Unit was formed in April 1949 at the Third Military Academy in Hoeryong, North Korea. The academy was specially designed to train commandos, and the 766th was originally designed to supervise North Korean light infantry ranger units. Over the next year, the 766th Unit received extensive training in unconventional warfare and amphibious warfare. During this time, the unit was expanded in size to 3,000 men in six battalions. Prior to the beginning of the war in June 1950, the 766th completed training and was moved to the front at Yangyang to support the KPA's 5th Division. The North Korean plan was to conduct amphibious landings in Chongdongjin and Imwonjin on the eastern coast using the 766th Regiment, in conjunction with the 549th Unit. These amphibious landings would harass the rear area of the Republic of Korea Army, providing supporting attacks to the planned frontal attack by the KPA's II Corps directly from the north. The 766th was in position by June 23 and prepared for the attack. The unit was moved to the ports of Wonsan and Kansong and loaded into ships. With the 3,000 men in the 766th, another 3,000 in the 549th, and 11,000 men in the KPA's 5th Division, the 17,000 North Korean troops outnumbered the Republic of Korea Army's (ROK) 8th Division's 6,866 by a ratio of 2.1 to 1. The combination of the frontal attack and the landings were expected to crush the ROK division and prevent reinforcements from moving in to support it. The regiment was split into three groups for the attack. Three battalions acted as spearheads for the 5th Division on land while two more battalions conducted the landings in Imwonjin. This 2,500 man force reassembled and then led the North Korean units south. In the meantime, the 3rd Battalion,