Operation Compass. Assault on Tobruk, Libya, opens at 5.40 AM with an artillery barrage. Australian 6th Division sappers blast through the perimeter wire with Bangalore torpedoes and fill in antitank ditches, allowing 18 Matilda tanks and some captured Italian M11 and M13 medium tanks to move through. As at Bardia, Allied infantry and tanks pick off Italian machinegun posts, artillery batteries and dug-in tanks from within the defensive perimeter. They reach within 2 miles of the town of Tobruk and shell Italian cruiser San Giorgio from cliffs overlooking the harbour. 3 squadrons of RAF Blenheims bomb the defenses continually. 8000 Italians are captured including the commander at Tobruk, General Petassi Manella, who refuses to surrender the garrison. Overnight, Italian bombers attack but only succeed in hitting a POW compound and killing 50-300 Italian prisoners.
Italian East Africa. 5th Indian Infantry Division, under British General Lewis Heath, advances 50 miles into Italian Eritrea from Kassala on the border with Sudan and captures the town of Aicota unopposed. General Heath sends part of 10th Indian Infantry Brigade, including 2nd battalion Highland Light Infantry, North to get behind well dug in Italian position at Keru.
Rescue tug HMS Englishman is sunk by German bombing 50 miles off the coast of County Donegal, Northwest Ireland (all 18 hands lost).