In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

One commander at this battle was almost killed by Henry de Bohun while riding alone in front of his lines, but saved himself by killing Bohun with a battle axe. The defending army was drawn up into three squares, and a series of pits with stakes at the bottom was dug in front of their line. After the Earl of Gloucester was killed on the second day of fighting, it turned into a rout and the losing commander was forced to flee to Dunbar Castle. FTP, name this battle fought south of Stirling Castle in the summer of 1314, in which Edward II's army was defeated by Robert Bruce.
History

An approximation of it named for Russell uses the TDS value to determine one of its parameters via the Langelier approximation, while one constant that appears in it has units of moles per kilogram to the one half power, according the Bates-Guggenheim convention. Along with Guggenheim, Scatchard and Bronsted improved upon this model by developing the SIT theory, and that model has a better fit than a modification of it named for Davies. This relationship assumes the existence of only long-range interactions, and it was extended to account for Brownian motion by Lars Onsager. It assumes that the solvent is structure-less and that the solution is dilute, and the theory behind it implies that the electrostatic potential falls off exponentially when r is greater than the atomic radius due to screening by counter ions. For 10 points, identify this equation which is used to calculate the activity coefficients, and is named for a German and a Dutch scientist.
Science

This god briefly regained life after his wife transformed into a kite to wave air into him. During the Middle Kingdom the god Ptah became assimilated with this god, and this god's son is typically depicted with the head of a falcon. Along with his brother the god of chaos this god was one of two sons of Geb and Nut and this god was also the father of Horus and husband of Isis. This god was killed by his brother Seth, who chopped up his body into many pieces. For 10 points, name this Egyptian god of the underworld.
Social Science