When listening to the narrative and the explanation that the Vampire Civil War took place at a major cataclysmic occurrance, I started reseaching possible happenings and the influences that were caused by these occurances. Just finding out what had happened to the Old Kingodm of Eygpt made me think could this have been used as an integral web in the story line of Vampire High.
The initial breakdown of the Old Kingdom was caused by a sudden, unanticipated, catastrophic reduction in the Nile floods over a period of two to three decades. This was so severe that famine gripped the country and paralyzed the political institutions. People were forced to commit unheard of atrocities such as eating their own children and violating the sacred sanctity of the royal dead. The Egyptian sage of that time Ipuwer gives a graphic description of the horrendous events of that time.

Lo, the desert claims the land Towns are ravaged, Upper Egypt became a wasteland

Lo, everyone's hair has fallen out
Lo, great and small say, 'I wish I were dead'

Lo, children of nobles are dashed against walls. Infants are put on high ground.  Food is lacking.    Wearers of fine linen are beaten.  Ladies suffer like maidservants.

Lo, those who were entombed are cast on high grounds.  Men stir up strife unopposed.         Groaning is throughout the land, mingled with laments.  See now the land deprived of kingship.  What the pyramid hid is empty. The People are diminished.

Egyptologists concede that there can be no doubt that these texts relate to fact. There is incontrovertible evidence that this terrible famine was caused by the reduction of the Nile floods.
The scale of the failure of the floods is shown by the fact that the Faiyum, a lake of some 65 metres deep, dried up. This means that the lake actually evaporated over a period time. These low floods were related to global climatic cooling which reduced the amount of rainfall in Ethiopia and East Africa. In Iceland, researchers have detected a transition from birch and grassland vegetation to arctic conditions in about 2150 BC. This correlates with a shift to drier climate in south-eastern Europe c.2200 - 2100 BC. Also, the reappearance of oak at White Moss, UK, suggests fluctuating wetness in around 2190 - 1891 BC. In Italy, drier conditions are found around 2200-1900 BC in Lake Castglione. Dry spells have also been detected as far away as Western Tibet at Lake Sumxi.

The most tantalizing recent discovery, however, was made when scientists made a high-resolution study of dust deposition from Kajemarum Oasis in north-eastern Nigeria. The study conclusively revealed a pronounced shift in atmospheric circulation which occurred in and around 2150 BC. This data indicates that an abrupt, short-lived event of cold climate led to less rainfall and a reduction of water flow in a vast area extending from Tibet to Italy. This had catastrophic effects on such early state societies as the Egyptian Old Kingdom.
Long-term variations in Nile floods are beyond the perceptions of people. The Nile, today and during the prosperous times of the Old Kingdom, is regarded unquestionably as the source of life in Egypt. Therefore, the Nile can be considered as the force which destroyed the civilization that it had nurtured. Inconceivable as it might be, the Nile is a temperamental river. The volume of flood discharges  varies wildly in episodes which range from decades to hundreds of years. Furthermore, there is the impact of freak years where the floods can be disastrously low or high.

The impact of a series of low floods, even if they occur over a few years, can cause distress, famine, plague and civil unrest in Egypt. Iin AD 967, a low flood caused a severe famine that left 600,000 people dead in and around Fustat, the capital of Egypt at that time. The famine lasted for two years and it was not until AD 971-2 that plentiful harvests returned. Once again, in 1201, low Nile floods followed by another low flood in 1202 caused a catastrophic famine.
This eyewitness account comes from Abdel-Latif Al-Baghdadi, a physician/scholar from Baghdad who was in Egypt from 1194 to AD 1200. He reported that people emigrated in crowds and that those who remained habitually ate human flesh,  parents even ate their own children so people reverted to cannibalism at that time to survive. Graves were ransacked for food, assassinations and robbery reigned unchecked, and noblewomen begged to be bought as slaves. Al-Baghdadi's account is almost an exact copy of that recorded by Ankhtifi, more than 3000 years earlier.
All of Upper Egypt was dying of hunger, to such an extent that people reverted to eating their children. The entire country starved,  like a starved grasshopper, with people going to the north and to the south in search of grain.
The lower  Nile episode that devastated the Old Kingdom was, however, of greater magnitude and duration than that of 967 or AD 1201.

Eygptian Art of Self Defense
Eygptian History and Vampires
History of Vampires
Geography of Vampires