The Romulan Factions refer to the governments that arose after the collapse of the Old Romulan Star Empire with the supernova of the star of Romulus in 2387. While the new Romulan Star Empire styles itself a seamless continuation, it claims less than half the territory of the past, and both the Romulan Free State and the Romulan Republic have been recognised as legitimate governments by the powers of the Alpha and Beta Quadrants. The three factions have been in something of a détente for over a decade, vying for supremacy with Romulan subtlety rather than force.
The decline of the old Empire began arguably with the end of the Dominion War, where the weakened and frustrated state of the Romulan Navy paved the way for the attempted coup of Shinzon of Remus. While the coup was unsuccessful, it exposed fractures within the Empire, wiped out almost the entire Senate, and triggered a fresh era of paranoia in the surviving government. As such, when Romulan scientists reported the coming supernova of their home system's star, these reports were kept secret from the general populace and other major powers.
This made the evacuation efforts, already an operation of unprecedented magnitude, even more complex. The forced relocations and seemingly nonsensical orders from the Senate led to several years of in-fighting between various factions of the Empire, and heightened tensions along the borders with both the United Federation of Planets and the Klingon Empire. The Romulan Empire even violated the Treaty of Algeron to evacuate refugees to the Romulan Neutral Zone, though this ultimately forced them to reveal the truth to the Federation and beseech them for aid. By this stage of 2384, it was apparent that at least 900 million Romulans could not be evacuated before the supernova without outside assistance. Despite internal opposition, the Federation offered the necessary aid, only to withdraw it later after their own crisis of the Attack on Mars.
The Romulans were left to save themselves. The only relief from the Federation was access to the old Neutral Zone for evacuations, and the eventual aid of Ambassador Spock, who perished in his successful efforts to mitigate the effect of the blast beyond the Romulus system. The loss of life was still astronomical, as was the loss of resources and damage to infrastructure, both physical and political.
The Romulan Senate's legitimacy hugely undermined, both by the loss of the seat of power and by their handling of the crisis. Though the Praetor and much of the Navy supported the remaining Senate as it reestablished itself on Rator III, there existed significant opposition to a simple continuation of power. A small but determined faction within the Senate itself rejected this continuation, relocating instead to the world of T'Met and establishing the so-called Romulan Free State. More worlds than expected pledged allegiance to this separate Senate, and it became apparent the Free State was supported by the Tal Shiar, who had found the Imperial Senate too intractable in the crisis.
This competition between the two Senates, one supported by the old navy and the other by the Tal Shiar, caused only more discontent among the worlds most distant from the old seats of power, those more likely to be ignored or harnessed for resources during the struggles. Many of the Romulan people had been left to fend for themselves, either in escaping the supernova or in their own governance as the central authorities struggled with the crisis. This paved the way for the rise to power of the third, more liberal faction: the Romulan Republic.
The new Romulan Star Empire styles itself as the natural successor to the old, though it lays claim to less than half its old territory. Years before the supernova itself, it made plans to relocate the centre of power to the nearby world of Rator III. The success of this continuation, both as a logistical undertaking and a claim to authority, has largely been due to the loyalty of the majority of the Romulan Star Navy, whose interests were largely heeded by the Senate and which thus had no reason to splinter in its support. The downside is that the Empire retains most of the blame for any mishandling of the evacuation, which has allowed for the rise of rival factions. While not in open conflict with the Free State and Republic, the Empire does not formally recognise them as legitimate, and has not ceded its claims to their territories. By maintaining the same trappings and structures of government of the Empire of old, the Romulan Star Empire persists in projecting itself as a seamless continuation, and expects to be treated as such.
Romulan Free State and the Tal Shiar
Mismanagement of the crisis of the supernova by the Romulan Senate led to multiple discontented factions. The Free State arose out of one of the more powerful wings of the Senate who refused to join the new government on Rator III. While they were not the only senators to break off, they were one of the largest groups and, more importantly, enjoyed the support of the Tal Shiar. The Tal Shiar themselves had found the Imperial Senate intractable during the crisis, Shinzon's attempted coup leaving them with fewer hooks in the reformed government. Unable to push their agenda or respond to the supernova crisis as they wished, they withdrew from the establishment of a new government on Rator III and looked elsewhere. The founders of the Free State were senators of their choosing, or who had at least demonstrated shared interests and agendas. Where many other potential splinter factions collapsed, the Free State thrived with the backing of the Tal Shiar, their resources, and the naval power they had built up during the crisis in anticipation of just such an eventuality. While the Free State maintains a Senate and a Praetor, with power structures much like those of the old Empire, the Tal Shiar is more embedded in government than ever before, formally and informally, and drives the agenda.
As the Imperial government squabbled amongst itself and prioritised maintaining its own power throughout the crisis, border worlds and some more firebrand senators found themselves and their interests overlooked or outright ignored. Many inhabitants of the Romulan system escaped the supernova without the aid of the Navy, Empire, or the United Federation of Planets, surviving by only their own wits or the help of Romulan citizens who came to their aid of their own accord. These are the groups which formed the Romulan Republic, centered around a world they christened 'New Romulus'. Without any competing claims of legitimacy, they maintain a similar but far more democratic government structure, and have sought positive diplomatic relations within and without Romulan space. Those struggles for legitimacy between the Free State and the new Empire, and the friendship of governments such as the United Federation of Planets, have enabled the Republic's survival when other such liberalism among Romulans in the past has withered.