Silmarillion - Chapter 10 - Of the Sindar

[The Squatter of Amon Rûdh]

But Thingol describes those lands as "empty and wild" after the disruption of this chapter. Certainly in terms of the lands east of Doriath, primarily Ossiriand, the Nandorin population has been decimated and largely driven out, as Chapter 10 describes. The situation before the attack of the Orc hosts after Morgoth's return is less clear in Hithlum and Dorthonion, but Thingol clearly thinks of these as his provinces, so that he grants the Noldor "leave to dwell" there.

The question is what the situation would have been had the Nandor remained in possession of Ossiriand under Thingol's lordship, and had Thingol himself been in a stronger position.

1200-50

§18 In this time the power of Elwë and Melian reached over all Beleriand. Elu Thingol he was called in the tongue of his people, King Greymantle, and all the Elves of Beleriand from the mariners of Círdan to the wandering huntsmen of the Blue Mountains took him for lord.

The Grey Annals. HME VII p. 9.

The Grey Annals also contain a passage not included in The Silmarillion as published, which makes more explicit Thingol's position concerning Beleriand as a whole.

For it entered into the heart of King Thingol to regret the days of peace when he was high lord of all the land and its peoples. Wide were the countries of Beleriand and many empty and wild, and yet he welcomed not with a full heart the coming of so many princes in might out of the West, eager for new realms.

§48 Thus was there from the first a coolness between him and the sons of Fëanor, whereas the closest friendship was needed if Morgoth was to be withstood; for the sons of Fëanor were ever unwilling to accept the overlordship of Thingol, and would ask for no leave where they might dwell or might pass. When, therefore, ere long (by treachery and ill will as later is told) the full tale of the deeds in Valinor became known in Beleriand, there was rather enmity than alliance between Doriath and the House of Fëanor; and this bitterness Morgoth eagerly inflamed by all means that he could find.

Ibid., p.19.

This provides further explanation of his message to the Noldor in Chapter 13, in which he grants them Hithlum and Dorthonion as though these are lands over which his rule extends, and presages more explicitly how the respective positions of Thingol and the Fëanoreans will deteriorate as events unfold. Although it's getting somewhat ahead of the situation, I note that Maedhros responds to Thingol's message by saying "A king is he that can hold his own, or else his title is vain. Thingol does but grant us lands where his power does not run." There is more than a hint in this passage that the Fëanorians would have been quite prepared to take lands by force, and I doubt that Thingol would have taken such a move lying down.

It was probably overstating the case to say that the Sindar would have to be dispossessed had they not already been driven out by Morgoth; but I think that there is plenty in these two chapters to suggest that Thingol and the Noldor could easily have become embroiled in a war over this territory had not the orcs severely curtailed his power. Certainly there is enough here to demonstrate how unrealistic was the Noldorin scheme: they presumed that lands in Beleriand would simply be there for the taking, but instead discovered on their arrival that Elwë had become a powerful king, who regarded himself as the rightful ruler of the very lands that they would have as realms. This is one of the many tensions that will cause defeat at the hands of Morgoth to become a still greater tragedy. This was the point I was trying to make, rather than that the Noldor would naturally themselves dispossess all the Sindar.