Why is the Horn of Africa densely populated?

In ancient and medieval times, the Horn of Africa was referred to as the Bilad al Barbar ("Land of the Berbers"). It is also known as the Somali peninsula or, in the Somali language, Geeska Afrika, Jasiiradda Soomaali or Gacandhulka Soomaali.  The name Horn of Africa is sometimes shortened to HoA

Explanation:

the proximity of water was an advantage to western europe and its culture was able to flourish as a result. trade and travel by sea were easier and safer in historical times.

1. there are no mountains to protect it from the sea

2. and its has wet cool summers and wet, mild winters.