After the successful rebellion which saw the Aleph subsector free itself from Imperial rule the collection of worlds that were to became known as “The Federacy” had largely abjured themselves from the wider events of the sector. Whilst the hawkish Votann of Hartak wanted to continue the struggle and free ever more worlds from the Imperial yoke they were opposed by the other Federal governments who wished to focus on rebuilding their war-scarred societies and strengthening their defences against the ever present threat of an Imperial crusade, a crusade they had no stomach in provoking through further expansion.
As the Federal worlds rebuilt and prospered and the horrors of war became a distant memory the attitudes of their peoples gradually shifted. The bellicose Leagues of Hartak became ever more difficult to silence and they gained support amongst the fierce Sartosans and proud martial culture of Cerberex. The Tau Empire also began to place ever increasing pressure on the Federal Council, pointing out their continued alliance and military support was contingent on reciprocity. Why should the Tau Empire guarantee the Federacy's independence from the Imperium when they were receiving nothing tangible in return? Behind closed doors ambassadors from the Aeldari also quietly urging the Federacy to action.
With great reluctance the Federal Council had authorised the Leagues of Hartak to mobilise their fleet in support of the Tau invasion of New Cerberex. Although they hadn't engaged in direct action the fleets presence in the Zadoc subsector had contributed to an overwhelming Alliance naval superiority that discouraged the overstretched Imperial Navy from risking the loss of any more of their ships contesting the invasion.
Following the Tau win on New Cerberex it was now the Federacy's turn to get its hands dirty once more. Spearheaded with legions from the Leagues of Hartak the Federacy were to provide the primary forces and logistical support for the invasion of Hylas. The Votann of Hartak had built up a formidable and well equipped professional army and were keen to show what it could do.
Masters of their own icy homeworld the Kȃhls of Hartak immediately saw the opportunity to exploit the sparse defences and patchy sensor net of the world's southern polar region. In secret they would gradually build up a base in the hostile frozen wasteland that their own equipment and tactics were so uniquely well adapted for before striking north in a rapid blitz that would, hopefully, take the Imperium completely unawares.
Hylas had been relatively peaceful for years, following the end of the long and punishing war against the ork menace in 018M42. However, the infrastructure of the world was still recovering, and the populace remained scarred by the brutality of the battle against the greenskins. By 024M42 the Imperial commanders were well aware that Hylas would be the next target for the Tau Empire, and with the imperial fleet still in refit, Sector General lord Baran Price expected it to be sooner rather than later.
To defend the world Hylas forces were quickly organised and reinforced by Librian Guard, now renamed the 2nd Aleph Wardens regiment as the stain of the fall of Libria was wiped off imperial records. General Van Dorn, a veteran with intimate knowledge of Hylas, was brought out of retirement to deal with the imminent Tau invasion. Defences were prepared around likely drop zones and lines of advance. With nothing else to do, the Imperium waited.
The first inkling of an invasion wasn't Tau mantas sweeping in from orbit, but the loss of communication with Ice Station 57K in the far south of the world in the frozen wastes south of the Beng plains. Information was slow in coming through, but Van Dorn was aware this was likely a hostile attack so redeployed some of his Aleph Warden forces to Beng itself.
Further south the imperial patrols posted to the area had suddenly been assaulted by armoured figures quite unlike the Tau, who appeared very at home in the icy terrain, utilising void suits and hardy vehicles running on large wheels, perfect for the snow and ice. This was the Hartak 107th Ice foxes, a regiment of abhumans from the Federacy, which the Librians had faced before many years previously on Myrentas II. The initial skirmishes with patrols almost stymied the Federal plans to cut off communications, but at a critical moment the morale of the Aleph Wardens regiment collapsed, and the units fled in disarray.
Having dealt with the patrols and established a bridgehead on the world, with the Imperium still unaware that the Federacy were leading the assault and had already invaded Hylas, the Hartak forces pushed on to Benger hoping it would be relatively undefended. Thanks to Van Dorn's awareness however, Benger was fully defended by imperial guard forces, and the tanks of the Aleph Wardens proved to have effective firepower against the Votann forces of Hartak, though their lascannons were woefully inaccurate.
Poor accuracy from the defenders and poor morale in the cold southern settlement rather than overwhelming force or stunning tactics saw the city fall to the Federacy by 1804.024M42. In fact the Hartak force had been over confident, and the commander received criticism from Federal command for rushing into the city and incurring higher casualties than was necessary. On the imperial side there was despondency as yet again the Alliance of the Federacy and Tau had the imperial guard on the defensive, and had defeated an entrenched defensive force.
To address the immediate situation General Van Dorn appealed for Astartes aid, and the Sky Lords were the first to respond, deploying a company to the world to act as a rapid reaction force. Meanwhile the forces of the Federacy continued to build up their base near the south pole, their supply ships unhindered by the imperial navy, and the imperial defenders on Hylas unable to interfere. A new war for Hylas had begun.
