The Blitz

There is another heavy raid on Plymouth.

Damage in Plymouth from the Blitz.

Diplomatic Relations

The Soviets protest to Germany over violations of Soviet air space by high-altitude reconnaissance aircraft. There have been 80 such incidents between March 17 and April 18.

Greece

The German forces begin to arrive at the Thermopylae position. Evacuation of British forces begins.

Italian East Africa

The British storm the defenses of Dessie.

Mediterranean

• German air attacks sink numerous ships throughout the area. Lost are the Greek steamer Athinai (968t) in Itea Harbor, the Greek steamer Avlis (223t) at Raphina, the Greek steamer Aghios Markos (4514t) at Peristeri, Salamis Island, the Greek steamer Frinton (1361t) at Megalo Lefko, the Greek steamer Ioannis Nomicos (637t) at Antikyra, Gulf of Corinth, the Greek steamer Pancration (2171t) at Milos, the Greek hospital ship Sokratis (1134t), the Greek tanker Thedol 2 (657t) at Antikyra, the Greek steamer Thraki (1151t) near Sombraina, Gulf of Corinth, the Greek steamer Thassos (1565t) at Megara and the Greek steamer Messarya Nomikou (985t) at Nafpactos.
• The Yugoslavian steamer Serafin Topic (4294t) is interned by Algerian authorities at Oran. The ship is later renamed Cosalla for Italian use.