Board Thread:Questions and Answers/@comment-26353401-20160416224534

Hello! Here is my complete Undertale timeline theory. Some of this isn't confirmed but I would still suspect it.

Anyway, let's begin.

1991-1995 - (Note that these can be in different years.) The monsters lose the war against the humans, and are sent underground. Asriel Dreemurr is born. Chara falls into the Underground.

1996-2003 - The death of Chara and Asriel. Gaster is hired as Royal Scientist. Toriel resigns as queen and escapes to the Ruins. The second and third humans fall, and are killed by Asgore.

2004-2007 - Gaster is eradicated from existence by the CORE, possibly the birth of Papyrus and Sans as a result. The fourth, fifth and sixth humans fall and are killed by Asgore. Undyne starts being trained by Asgore. The Snowdin civilians leave the Ruins (yes, they were once in the Ruins, as stated by the shopkeeper.) and head to Snowdin.

2008-2011 - Alphys is hired as Royal Scientist. Sans and Papyrus arrive at Snowdin. Undyne is promoted to leader of the Royal Guard. The seventh human falls, and is killed by Asgore. Alphys creates Flowey. Undyne meets Alphys at the garbage dump, and they become friends.

Skip to 2015, as I have no idea what would happen from 2012 to 2014.

2015- Gaster reappears somehow. Alphys creates the Amalgamates. Toriel befriends Sans. Frisk falls into the Underground. Asriel is temporarily brought back before reverting to Flowey. The monsters escape the Underground with help from Frisk and Asriel.

If you have anything for me to put in, please let me know! 