Lion = Babylon see Daniel 2. The lion was symbolic for Babylon even outside the Bible.
Bear = Medo-Persia see Daniel 7:5 and Daniel 8:20 the three ribs are the three principle powers they conquered. Lydia, Babylon, and Egypt.
Leopard = Greece. Alexander is said to have had a leopard skin as a saddle. 4 wings because he moved his army very fast. 20,000 miles in 10 years. 4 heads because when he died, his kingdom was divided among his four generals. They became the four divisions of the Greek Empire.
Diverse – Iron teeth and 10 horns see Daniel 7:7. Revelations 17:12 the ten horns are ten kings or kingdoms. Iron because Rome was the iron legs in Daniel 2. Rome is the ten toes for it was divided up into 10 kingdoms, Alamanni (Germany), Ostrogoths (Destroyed), Franks (France), Visigoth (Spain), Vandals (Destroyed), Heruli (Destroyed), Burgundian (Switzerland), Suevi (Portugal), Lombards (Italy), Anglo-Saxons (England). With the three kingdoms destroyed the 10 kingdoms become 7 kingdoms.
NOTE: Are the 7 churches the the religious history, the 7 seals the political history, and the 7 trumpets the military history?