I am going to talk about the latest civlization that existed in Greece before the end of the bronze age, the Mycenean civilization. It is named after the most important city, Mycenae. The mycenaeans migrated to Greece from the Balkans, defeating the local peasantry there who were aremed with stone tools with their bronze weapons. The Mycenaeans were tall and wore beards, unlike the Minoans who were small and cleanshaven. It is probable that many minoan refugees flooded to Anatolia, like the Carians which had been driven out of the Cyclades by the legendary king Minos (That was how the region of Caria came to be called, in southwestern anatolia in classical times).
The Mycenaeans replaced the Minoan civilization which was destroyed at about 1400 bc, taking control of the islands and creating large palaces similar to the Minoan ones, except they were generally larger but lacked the refinement of the Minoans'.
The Mycenaean civilization was full of rich and competing kindoms, such as Lacedaemon and those in what would be called Boetia. Of course there were depressed areas, such as Arcadia and Attica. The reason why Athens was so rich and powerful in classical times was because Attica was not an area competed for in Mycenean times and the dark ages, so the people could settle down and create rich cities (Athens was founded in Mycenaean times).
The Mycenaeans created cities on fortified citadels on hills, which was called an acropolis, from the word polis, which meant city. This acropolis continued to be in use in classical times, but it also had turned into a religious center.
The Mycenaeans created a warrior-like society, a society which valued valour highly and the act of dishonoring someone or his wife was a major offense. The regular Mycenaean warrior carried a bronze tipped javelin or throwing spear, a large leather shield, and sometimes a cuirass. The wealthy warriors wore a cuirass, shoulder guards, and had special helmets made of ivory from boar's tusks.
Homer reffered to the Mycenaeans in his poems as "Argives, Danaans, and Aecheans. It is very possible that Troy was a real city beseiged by the mycenaeans, and if the event did occur at all,it is likely that one of the underlying reasons why the Greeks attacked the city may have been because Troy thereatened their trade routes to the black sea, as Troy was placed at a very strategic point near the Hellespont (modern Dardanelles).
Soon after the Trojan war, which is estimated to have taken place around 1200bc, Mycenaean civilization collapsed, as new barbarians from the north, the most important of the tribes were called the Dorians, who founded classical Sparata, invaded. The Dorians were able to defeat the Mycenaeans in battle with their superior iron weapons, and there is evidence thaat at abaotu 1100 bc the palaces that had symbolized much of the Mycenaean culture was burned. Mycenaean refugees ended up flocking to western Anatolia, and founded cities there that would later be called Ionian. The Ionians preserved much of the Mycenaean culture to the classical times, and they were their true descendendants.
On mainland Greece, the Dark Age had broken out, and the chaos and turbulence there would not subside untill the start of the Archaic Period.