3. What theories do historians have about why the Minoan culture declined after 1500 B. C.

The theories regarding the fall of Minoan Culture are - Volcanic eruption and series of disaster.

Explanation:

The centre of Minoan civilization, the Crete island was thought of being destroyed by a huge volcanic eruption by many historians, though it lacks confirmation.

Minoan Eruption theory was proposed by Greek archaeologist Spyridon Marinatos (1935-39). The great volcanic eruption of Thera island after 1500 B. C. which was about 100km away from Crete may have destroyed the Minoan civilization.

Though there is a clash of opinion between historians that the eruption could have been one of the causes of Minoan downfall.

The Minoan culture was the first well developed civilization in Europe. It was located in the Aegean Sea, on the island of Crete. The small but prosperous and advanced civilization suddenly seized to exist though, and the reasons for it are still debatable. The main theories are that it was the volcano Thera with its enormous eruption that caused huge damage and led to the the decline. Others suggest that it was a massive tsunami that swiped through the island and suddenly ended the Minoan civilization. Other theory is that the decline was caused by an invasion from Doric people from the mainland.