The Unification War started with Lao Anbiao's nomination as Chairperson in the elections of 2505, which triggered a declaration of secession from the Alliance from many colony worlds. Leaders of the “Independent Faction” had long been waiting for an event that might unite the colonies against unification forces, and Anbiao’s hard-lined adherence to an Alliance of all colonized worlds was, most believed, the catalyst necessary.
Once the election returns were certain, a special Independent convention declared "that the union now subsisting under the name of the "Interstellar Anglo-Sino Alliance of Colonized Worlds' is hereby dissolved." By February 1, 2506, six more systems had seceded. On February 7, the seven systems adopted a provisional constitution for the Independent Colonies. The remaining colonial systems as yet remained in the Alliance.
February 9, 2506 - The coalition of Independent Colonies is formed (seven border systems are announced as members).
April 12, 2506 - Independents open fire upon Federal troops stationed on the IAV Sumter on patrol on the Athens moons. The Unification War begins.
April 17, 2506 - Verbena secedes from the Alliance, followed within 5 weeks by three additional systems who are, as a whole, much closer to the Core worlds than the original Independent colonies, bringing the total number of 'officially independent' systems to eleven. In an attempt to prevent more colonial systems from joining the Independents, the Alliance directorate passes the Crighton-Jihau Resolution, which stated that further successions would lead to stiff economic sanctions and tariffs.
April 19, 2506 - The Alliance directorate issues a blockade against Independent ports. For the duration of the war the blockade limits the ability of the rural Colonies to stay well-supplied in its war against the industrialized Core worlds.
July 21, 2506 - An Independent force has assembled on Verbena. Alliance troops move against Verbena under General Irvin. Independent General Prudence Vaughn resists the Alliance attacks with a much smaller force and Alliance troops fall back to Osiris.
July 27, 2506 - The Alliance directorate appoints Geoffrey Devchenko as Commander of the Sihnon Peacekeeping Force and follow this in November with appointment as general-in-chief of all Alliance forces. Devchenko responds, "I can do it all."
April, 2507 - An Independent surprise attack by underground resistance fighters on General Yu Kwan's unprepared troops on Boros results in 13,000 Alliance troops killed and wounded. Chairperson Anbiao is pressured to relieve Kwan but resists.
May, 2507 - Independent forces are driven from New Melbourne, holding that key strategic system for the Alliance.
August, 2507 - Under Devchenko’s successor, General Hildebrand, 75,000 Federals are defeated by 55,000 Independents under General Prudence Vaughn and General Harold Biao at the second Battle of Verbena. Once again the Alliance Army retreats to Osiris.
September, 2507 - Li invades the Core worlds through the Poseidon Nebula with 550,000 troops, en route to Osiris. Alliance forces under the command of Devchenko pursues Li. Chairperson Anbiao restores Devchenko, who wins a bloody, pyrrhic victory at the Battle of Tietam near Sihnon on September 17. Li's army returns to Verbena. Devchenko fails to “follow up on the Tietam victory” and is replaced by General Evan Ambrose.
December, 2507 - General Ambrose suffers a costly defeat on Verbena, with a loss of 12,000-plus troops after 14 frontal assaults. Independent losses are around 5,000.
January 25, 2508 - The Alliance directorate appoints General Etienne Mordeau as Commander of the Core Alliance force, replacing Ambrose. General Kwan is placed in command of the Border Alliance forces.
March 3, 2508 - The Alliance Directorate enacts a wartime draft, but exempts those who pay a fee or provide a suitable substitute draftee.
May, 2508 - Alliance forces under General Mordeau are decisively defeated by Prudence Vaughn's much smaller forces at the Battle of Three Hills as a result of Vaughn's brilliant tactics, although General Vaughn is mortally wounded by friendly fire. Mordeau retreats. Alliance losses are 17,000 killed, wounded and missing out of 130,000. The Independents, 13,000 out of 60,000.
May 20, 2508 - The Independents suffer a huge blow as Prudence Vaughn dies from her wounds. "I have lost my right arm," General Li laments.
June 3, 2508 - General Li (with 75,000 Independents) launches his second major offensive.
June 28, 2508 - The Alliance appoints General Jonah Shaker as commander of Alliance forces, replacing Mordeau. Shaker is the 5th man to command the Alliance forces in less than a year.
July, 2508 - The tide of war turns. Shaker stops Li's invasion of Alliance-held territory at the Battle of Greenleaf, inflicting massive casualties on Li's forces (and taking them in turn) again forcing Li to retreat; this time to Hera.
August, 2508 - Bellerophon, the last Independent planet with easy access to both Core and Border worlds, surrenders to General Kwan after a six week campaign that ends at the city of New Madrid. With the Alliance now in control of all major shipping routes, the Independents are effectively split in two. Nearby Santo colony falls within weeks of Bellerophon's capitulation.
October, 2508 - The Directorate appoints General Kwan to command all operations in the border worlds. Independent resistance in the border worlds is stretched thin and rendered ineffective by the end of the year.
December, 2508 - Alliance and Independent troops pinned down without supplies outside of New Kasmir.
March, 2509 - The Alliance directorate appoints General Kwan to command all of the armies of the Alliance.
May-December, 2509 - The beginning of a massive, coordinated campaign involving all the Alliance force. In Verbena, Kwan moves to engage Li, beginning a war of attrition that will include major battles at Whitefall, Silverhold Colonies, and Saint Albans. An attempt to outflank Li from the outlying systems fails due to the fact that Alliance forces are 'corked' within the unnavigable Bermuda Hundred Nebula, but Yu Kwan is tenacious and continues to press Li’s forces in Verbena and other Core systems such as Hera.
August, 2510 - Kwan eventually manages to force the Independent forces to overextend, pinning a large force down in the Siege of Du Khang and, after two failed attempts, finally finds a commander -- Bernadette Sheridan-Hale -- who can clear the threat to the Core Systems.
September, 2510 - An unresisting Persephone is ‘captured’ by Haas, who drives for the core worlds, leading forces that lay waste to much of the Georgia System (there are rumors of the using biological weapons, supported by the fact that Haas is currently working Durran Haymer. When Haas' troops turn to approach the Verbena system from the direction of the colony worlds (thus cutting off Independent supply lines) it is the end for Li and his men and with them, the Independents -- cut off, Li cannot move to reinforce the troops on Hera.
February, 2511 - Alliance forces begin a general advance on Hera, culminating in the battle of Serenity Valley, one the last and bloodiest of the major battles of the war. The battle lasts two months.
May, 2511 - Most of the remaining Independent forces surrender. Over 6,200,000 died in the war, disease killing twice as many as those lost in battle.
The Allied systems had won. Advantages widely believed to have contributed to the Alliance's success include:
The war officially ends in 2511.
The Battle of Paito Ranch, fought on May 23, 2511 on the colony world of Shadow was the last land battle of the war and, ironically, ended with an Independent victory. All Independent land forces had surrendered by June 2511, though Independent interstellar units surrendered as late as November of 2511.