Chapter 10
Of the Sindar
While Melkor/Morgoth had been imprisoned and the Vanyar and Noldor and Teleri had been living in Aman, the rest of Middle-earth had not been idle. Mainly, Thingol/Elwe had been busy getting his people together in Middle-earth and setting up a kingdom of his own. His people were known as the Sindar, and while they had never seen Aman or the light of the Two Trees, they became fair and wise under the leadership of Thingol and the teachings of Melian their angel queen. In the starlit lands of Middle-earth, before the creation of the Sun and Moon, Thingol and Melian had a daughter named Luthien. She was their only child, and the fairest person to have ever lived.
While Morgoth was imprisoned, the Dwarves had also been busy in Middle-earth. The line of Durin went to the Misty Mountains and carved out (literally) the kingdom of Khazad-dum, which the Elves knew as Moria. Closer to Beleriand, the Dwarves of the Blue Mountains had their first encounters with the Elves.
The Elves, of course, were amazed to find other people who could talk. They weren't great at learning the Dwarvish language, but the Dwarves picked up Elvish fairly quickly and the two groups began to trade.
Melian, being one of the Maiar, had much foresight and told her husband that their time of peace would not last forever. Thingol therefore hired the Dwarves to build him a fortified city. The Dwarves, unsurprisingly, made it underground, and it was a hidden city of a thousand caves. The realm of Thingol and Melian, including the city and the forest around it, was named Doriath.
Once the city's structure was finished, the Elves and Dwarves worked together to make it beautiful. The stone pillars that upheld the cavern's ceiling were carved to look like trees, which Melian's nightingales rested in when they weren't singing. The walls were painted with scenes of Aman and the great deeds of the Valar, and the city became a little piece of Valinor on Middle-earth.
It had been a good idea to take Melian's advice and build that city, for the time of peace was indeed ending. As the time of Morgoth's imprisonment was coming to an end, Orcs and other fell creatures began multiplying in Beleriand. The Sindar once again sought the help of the Dwarves, this time to make weapons and armor. The unparalleled craftsmanship of the Dwarves helped them clear out all the fell creatures around their city, but from then on it was clear that the time of peace was over. Thingol's armories were now always filled with shining swords and armor.
The Sindar devised their own system of writing during this time, which the Dwarves helped spread across the rest of Middle-earth. The Sindar themselves did not write much about their lovely city during this time, however, for they were too busy enjoying it. For things of beauty are their own record while they last, and it is only when they are destroyed or in peril that they pass into song.
But at last we catch up to present events and the end of even this watchful peace. Morgoth and Ungoliant fled into Middle-earth after destroying the Two Trees, and when Ungoliant was driven off by the Balrogs, she settled down and started her family right next to Thingol's kingdom. It was only the power of Melian that prevented her and her kids from wandering in and having all the Sindar as snacks.
Morgoth also returned to Angband, which was a mere 150 leagues away from Doriath. His first act as their new neighbor was to send a massive army into Thingol's kingdom. The Sindar defeated them, but Thingol and Melian decided that something needed to be done. Thingol summoned all his people to live in his city or the small region around it, and Melian put forth her power into walling it off with a circle of enchantments. No one could enter Doriath against the will of Melian or Thingol, unless they were more powerful than Melian. And thus Doriath was safe, while the servants of Morgoth roamed as they wished outside.