What are some instances in history where two forces battle but

The Jin-Song Wars came to an end when the Mongols conquered the Jin, and then the Song.

Bump. Idk of any but i'd love to

>>2736411
Manchu invasion of Ming? I don't know of any 3-way battles, but there a fuck ton of multilateral conflicts.

>>2736411
Not a person disrupting the battle, but I think it's interesting.
https://en.wikipedia.org/wiki/Eclipse_of_Thales
>just as the battle was growing warm, day was on a sudden changed into night.
>The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.

>>2736534
Eclipse are cool because they're often the only truly confirmable event we have.

>>2736411
That time Andrew Jackson got involved during that Indian civil war

>>2736411
Battle of Sekigahara and the battle of Bosworth field. 2 battles that ended a civil war on an island, both ended when a lord picked one side over another.

>>2736411
The Chinese Civil War interrupted by Japan was a rollicking good time.

>>2736411
The on again off again centuries-spanning Roman-Persian Wars were interrupted by Arab nomads conquering huge chunks of both empires.

>>2736411
Timurid invasion halted Ottoman conquest of Byzantium.

>>2736411
the rashidun disrupting the byzantine sassanid conflict

>>2736411
Maybe Gaius Popillius Laenas counts
>After receiving the submission of the inhabitants of Memphis and of the rest of the Egyptian people, some submitting voluntarily, others under threats, [Antiochus] marched by easy stages towards Alexandria. After crossing the river at Eleusis, about four miles from Alexandria, he was met by the Roman commissioners, to whom he gave a friendly greeting and held out his hand to Popilius. Popilius, however, placed in his hand the tablets on which was written the decree of the senate and told him first of all to read it. After reading it through, he said he would call his friends into council and consider what he ought to do. Popilius, stern and imperious as ever, drew a circle round the king with the stick he was carrying and said, "Before you step out of that circle give me a reply to lay before the senate." For a few moments he hesitated, astounded at such a peremptory order, and at last replied, "I will do what the senate thinks right." Not till then did Popilius extend his hand to the king as to a friend and ally. Antiochus evacuated Egypt at the appointed date, and the commissioners exerted their authority to establish a lasting concord between the brothers, as they had as yet hardly made peace with each other. Ab Urbe Condita, xlv.12.