The cities of Goranth and Brennan's Keep were two of the oldest city-states in the known world. Their early history is similar; they both started as small settlements, expanding over time until they both became large city-states dominating their immediate areas. While Goranth concentrated on mercantile and trade with other nations, Brennan's Keep showed curiosity in the world and thus developed a more scientific/mechanistic/industrial bent. Goranth's natural harbour and access to markets further south allowed Goranth to outstrip Brennan's Keep in the mercantile trade, becoming the larger of the two.
With Goranth's rise in the mercantile trade, Brennan's Keep slowly descended towards a much smaller power in the area. Fearing a possible future invasion, Brennan's Keep looked to find a mechanism to deter any future invasion rather than resist an existing invasion.
Brennan's Keep already had a vital industry in supplying much sought-after herbs, spices, and other ingredients needed by mages. Brennan's Keep also provided much of the mechanisation throughout the area. Such items include ploughs, watermills, windmills, sawmills, and, to a lesser extent, mining equipment and wagons.
The Brennan answer to deter any possible invasion was to construct and support a Great Library where scholars and sages could test the limits of and expand their knowledge. Caesar Brennan granted a large area of land and provided ongoing grants to build what is known as the Great Library. Surrounding the Great Library are the Houses of the Magi, one each for the various types of magic. These ongoing costs almost destroyed the House of Brennan, severely reducing its political power.
Over time, the magi's research far outstripped that of the known world, with much of any new renovations coming out of The Great Library.
Over time, Brennan's Keep became disenchanted with the Merchant Guilds of both Goranth and Brennan's Keep, believing these Guild Merchants were corrupt. Caroline Brennan imposed an export tax on all goods, leaving the Keep and import duty on all goods from Goranth. Over the next few years, Caroline invested this money in capital works and subsidies to new businesses.
As most of these new businesses were in direct competition with the Merchant Guilds, the Merchant Guild spent large amounts on lobbying various city lords to overturn the duties. They failed miserably, as city support was firmly behind Caroline. In retaliation, Caroline cut off Goranth's access to the library and exiled all Goranth scholars.
This led to the one and only armed conflict between Goranth and Brennan's Keep. The Merchant Guilds, not Goranth, organised a group of mercenaries and pirates into an army to invade Brennan's Keep.
The overwhelming nature of Brennan's Keep's defences totally destroyed the makeshift army in a matter of minutes, with no casualties for Brennan's Keep. Caesar's ideas behind Brennan Keep's defences showed a very firm ability to defend the Keep.
Caroline Brennan's overwhelming defeat of the Merchant Guild army allowed Caroline to purge all Guild Merchant activists in Brennan's Keep. Caroline managed to take back complete political control of Brennan's Keep.
Thus, Caroline's direct political influence rose due to this level of technology introduced by her ancestors. So, while small in stature, the pure destructive might Brennan's Keep could produce gave pause to any future invasions. This level of power, combined with the magic of the Magi, allowed Brennan's Keep to become one of the most beautiful and powerful city-states in the known world.
Since Goranth and Brennan's Keep were not directly competing, a much deeper friendship developed with the ruling families' inter-marrying. Not long after Breakaways proclamation of independence, Justin O'Malley came to Robert Brennan requesting help against a possible Breakaway invasion of Goranth. Robert didn't hesitate; thus, Breakaway was defeated through their combined might and aid from Dwarvenhelm.
Realising that the time of separate city-states was ending, Justin and Robert formed a mutual arrangement to support each other. Robert, who was more interested in maintaining the library, was quite happy becoming the junior partner in the Kingdom.