Complex sentence: With the fall of Matruh, Axis aircraft on the Matruh airfields were from the naval base at Alexandria, the British naval command was compelled to evacuate the Mediterranean Fleet, dispersing its force to several smaller eastern Mediterranean ports.
Split into simpler sentences: With the fall of Matruh, Axis aircraft that could be operating from the Matruh airfields would be from the naval base at Alexandria. In light of this threat the British naval command withdrew the Mediterranean Fleet, dispersing its force to several smaller eastern Mediterranean ports.