The Burning of the Ships was an event near the end of the First Age at Losgar after Fëanor and his followers stole the swanships of the Teleri from Alqualondë.
History
Prelude
After the death of Finwë and the theft of the Silmarils by Melkor, Fëanor and his seven sons swore an oath and went into exile. Many Ñoldor followed them, including the House of Fingolfin and the children of Finarfin.
They came to Alqualondë and Fëanor demanded to use the swanships of the Teleri. However, the Teleri refused and resisted when Fëanor tried to take them by force. The First Kinslaying took place and many of the Teleri were slain.
The event
In YT 1497, Fëanor, driven by mistrust of Fingolfin and fear that his followers might seek to return to Valinor, ordered the burning of the ships, and had left the host of Fingolfin behind. At dawn, Fëanor and his sons discovered the death of Amrod, who slept in the first burned ship. This was changed in The Silmarillion, which states that all seven of the Sons of Fëanor reached Middle-earth.
Aftermath
After the burning of the ships, Fëanor fought in the Dagor-nuin-Giliath and died afterward. Fingolfin, seeing the red light on the horizon, realised that he had been betrayed and led his people on a long and arduous trek over the Helcaraxë, during which many died. When he arrived in Middle-earth there was a risk of war between the followers of the Sons of Fëanor and Fingolfin's vengeful host. This was avoided when Fingon, determined to reunite the Ñoldor, rescued Maedhros from imprisonment on Thangorodrim. In recompense for the suffering of Fingolfin's people, Maedhros waived his claim and that of his brothers to be High King of the Ñoldor and removed his people to East Beleriand. The followers of Fingolfin remained in West Beleriand, therefore making the physical division of the Ñoldor, begun with the burning of the ships, permanent.
Translations
References
Location: Losgar