Short answers, pulled from the story.
The Italian invasion of British Somaliland was a military campaign fought from the 3rd to the 19th of August 1940, in which Italian, Eritrean and Somali forces invaded and occupied the British Somaliland Protectorate. It was part of the broader East African campaign of 1940-1941 and resulted in a British evacuation by sea from the port of Berbera.
Major-General Reade Godwin-Austen commanded the British and Commonwealth garrison during the invasion. Brigadier Arthur Chater had been the earlier military commander responsible for defence preparations, and General Archibald Wavell served as the overall theatre commander based in Egypt.
The Battle of Tug Argan was fought from the 11th to the 15th of August 1940 at a string of fortified hilltops in the Assa Hills. Italian forces with superior artillery gradually captured the British positions, including Mill Hill on the 12th of August; an attempted British counter-attack toward Mirgo Pass on the 14th of August failed, leading Godwin-Austen to order a general withdrawal.
The Royal Navy evacuated 7,140 people from Berbera, of whom 5,690 were front-line troops, 1,266 were civilians, and 184 were sick. The evacuation was completed by the early hours of the 18th of August 1940, with minimal losses during the embarkation itself.
Churchill believed that because British casualties were relatively low, the colony had not been vigorously defended, and he proposed a board of inquiry. Wavell refused to cooperate, arguing that Godwin-Austen had conducted a textbook withdrawal in the face of superior numbers; he sent Churchill a telegram stating that a large butcher's bill was not necessarily evidence of good tactics. The dispute contributed to Wavell being superseded by Claude Auchinleck in July 1941.
Britain retook British Somaliland in March 1941. On the 16th of March 1941, Operation Appearance saw two Sikh battalions of the Indian Army and a Somali commando detachment land on either side of Berbera from Aden; this was the first successful Allied amphibious landing on an occupied beach of the Second World War. Brigadier Chater was appointed Military Governor on the 8th of April 1941.