The Peace of Nicias (text here), signed by Athens and Sparta in 421 BCE, ended the first half of the Peloponnesian War. Two hawkish politicians, the Athenian Cleon and the Spartan Brasidas, had both died, making negotiation between the two city-states a possibility. Both sides agreed to return (most of) what they had gained durinf the prior ten years of fighting, and Athens was forced to make some concessions preventing it from maintaining its "Empire" - for example, while Athens could continue to collect tribute from their vassal states (which was the reason Sparta feared Athenian power in the first place), they could no longer force the vassals to become formal allies. It also had other stipulations, for example that all Greek temples would be open for any Greek to worship, and Athens would no longer exercise authority over the Delphic Oracle. Sparta, Athens, and the majority of both of their allies swore oaths (that is, civic representatives of the city-states swore on behalf of the city) that they would uphold the treaty, and pillars were set up in important sanctuaries like the Athenian Acropolis, the Lacedaemonian (i.e. Spartan) temple at Amycrae, and the sanctuary at Olympia, to commemorate the treaty.

The Peace was meant to last fifty years. Unfortunately, one of the main stipulations in favour of Athens, that the town of Amphipolis would be returned to Athens from Spartan control, along with a number of other stipulations, never took place. As well, some allied city-states on both sides of the War continued to fight one another, forcing the main players to choose sides, and some allies simply refused to swear to the treaty. The Peace managed to prevent direct hostilities between Athens and Sparta (while smaller-scale aggression still took place) for about six years before it collapsed entirely, and the second half of the war began.

The Hittite-Egyptian peace treaty (or [Treaty of Kadesh] (http://en.wikipedia.org/wiki/Egyptian%E2%80%93Hittite_peace_treaty)) is the oldest extant peace treaty. Thought to have been created c. 1259 BC, it was an agreement between Pharaoh Ramses II of Egypt and King Hattusili III of Hatti. Both the [Egyptian] (http://webcache.googleusercontent.com/search?q=cache:http://www.specialtyinterests.net/peacetreaty.html&gws_rd=cr&ei=YbD9VI-EN876aIiUgYAI) and [Hittite] (http://www.languageandlaw.org/TEXTS/CONST/KADESH.HTM) versions survive and have been translated. What is particularly interesting is that the versions differ slightly from one another, with the Egyptian explicitly stating a state of war between the two kingdoms and an apparent complete Egyptian victory with a Hittite surrender, while the Hittite version is slightly more guarded and suggests a more equal agreement.

A useful [journal] (https://www.britishmuseum.org/pdf/6a%20The%20Eternal%20Treaty.pdf) regarding the Hittite version, with a brief bibliography for further reading.

An even earlier example than Athens and Sparta is between the Ancient Egyptians and Hittities. They established a treaty after the battle of Kadesh in 1258BCE. This truce was never broken. Text from this treaty hangs at the UN today.

edit: I'm not sure how to link scholarly articles because I have access to them through my school, but I don't think everyone would be able to access them. So here's this

Alright, so in terms of pre-historical "histories", China has a doozie...

Of the semi-mythological 3 Sovereigns, the last and likely most important is Huangdi, the Yellow Emperor. There is significantly more information and documentation regarding this man than any of his other so-called "comtemporaries" – including given and ancestral names: Xuanyuan, and Gongsun, respectively. This has led many historians to conclude that Huangdi was, if still deeply steeped in mythological elements, at least significantly more historically rooted than his predecessors. As such he, rather than, say, Fuxi or Shennong, is often considered the first “true” monarch of what would eventually be China.

Traditionally, the Yellow Emperor augustly reigned from 2697 to 2597 BCE, which is to say a good, solid, suspiciously round hundred years of rule. He was born in a place called Shou Qiu, or “longevity hill” in what is now Shandong province in the northeast of the region. Shou Qiu clearly lived up to its name, as a century-long reign is quite the feat. Early in his life, young Xuanyuan moved from Shandong to Hebei where he became a farmer and local leader along the Yellow River in a region adjacent to the area of the Jiang River Shennong the Flame Emperor still reigned.

Though the Flame Emperor was revered for his many great deeds, he had become increasingly unable to control the factions that had sprung up under his rule. Attribute that, possibly, to his putrefying intestines brought about by his propensity to ingent any damn this he came upon tosee what it did. Or, perhaps, if we take the view than the Yandi was a line of Emperors, rather than merely the individual Shennong, it could have been a protracted period of mounting tensions coupled with ineffectual leadership. Such corruption and breakdown of Imperial power over the course of a dynasty is not much of a stretch to suggest, as it will in fact become the rule of the Chinese Empire, rather than some exception.

This factionalism, along with an ever-present tribalism, had devolved into a period of war throughout the region, and the Flame Emperor turned to Xuanyuan’s Youxiong tribe as a potential ally in quelling the unrest after suffering a major defeat. This defeat came at the hands of a figure known as Chi You, and his rebellious tribe, the Jiu Li, along with as many as 80 other tribes. Xuanyuan readily agreed to assist the routed Flame Emperor – after all, rebels in one’s adjacent region is rarely ever going to end well for your own principality... especially on the heels of defeating the major power of the region. Taking up arms, the combined forces of Youxiong and Shennong, known collectively as the Huaxia, amassed and met the Jiu Li in battle at a place called Zhuolu.

Victorious, the Shennong and Youxiong tribes established a capital at the site of their victory, Zhoulu, under the joint rule of the Flame and Yellow Emperors. The remnants of the Jiuli tribes were scattered and driven South out of central China, in the process splintering into two tribes that would come to be regarded as barbarians by the Huaxia, the Miao and the Li. It seemed, for a time, that life would return to peace, but that was not to be… at least not yet. Though the two rulers had been allies in battle, their newly minted co-ruler ship chafed at both of the Emperors’ senses of pride. Before long, the tense peace was broken and battle resumed, but this time between the Youxiong and Shennong forces. In a series of three clashes known as the Battles of Banquan, the Shennong armies were defeated and surrendered to the supremacy of the Yellow Emperor’s rule. The Flame Emperor was thus relegated to the sidelines and, of course, eventual death by poison reeds.

United now in peace, the two tribes formalized their union under the Yellow Emperor and took the name of their alliance, the Huaxia, as the name of their combined people. Huangdi proved the magnanimous nature of his rule through teaching his people to build shelter, tame wild animals, and grow what would become the five Chinese cereals: soybeans, wheat, broomcorn, foxtail millet, and – of course – rice. Further innovations for his people include the beginnings of astronomy, a revised calendar using lunar cycles that is largely still used today, mathematics, a legal code… and an early version of soccer. Huangdi reigned over his land , supposedly, for 100 years, taking 4 wives and fathering 25 sons. Approaching the end of his life, he was visited by two legendary creatures. The first was a horned lion, covered in flame called the Qilin. Sometimes referred to as a “Chinese unicorn,” the qilin would appear only with the imminent arrival or passing of an august ruler or visionary. Though this might sound ominous, it was actually taken to be a sign of good fortune, prosperity, and serenity. The second animal he Huangdi encountered was a phoenix. Though in the West, we typically associate the phoenix as the fiery bird of death and rebirth, the Chinese ideation of the bird is a symbol of the Cosmos, especially when it is balance. It would appear only to people or places with the utmost peace and prosperity. The message was clear: the Yellow Emperor had brought tranquility, prosperity, and august leadership to the Huaxia people… and now his time on Earth was at its end.

Giles, H. 1898. A Chinese Biographicla Dictionary. London: Bernard-Karitch. Retrieved from: https://archive.org/stream/achinesebiograp00gilegoog#page/n3/mode/2up.

Sima, Qian. The Records of the Grand Historian (史記）。 Retrieved from: http://ctext.org/shiji.

Sometime around 2400 BCE, there was a land dispute between the Sumerian city states of Lagash and Umma. This dispute was mediated by a King (ensi) of Ur named Mesilim. Apparently the truce was quickly broken and hostilities were soon resumed.