In the years between 2178 and 2243, Terran society and technology underwent rapid and dramatic evolution. Some of the socio-political events have been described. But of all these, it was the concentration of the Covenantists upon attaining high levels of education amongst the people which had the most profound effects. By the lime Terra was admitted to the High Republic in 2243, ils technology was fully the equal of that of the OutPlanets.

By 2275, Terran expertise began to outstrip the others, and continued emphasis upon education had resulted in a population with a level of education and technical training unparalleled in the rest of humanity. In 2275, the OutPlanet communities of the Solarian System joined with Terra to form the tiny Union of Planets. The Terran Union never formed the intention to found an interstellar empire. But the reputation of Terran culture, government, diplomacy, and industrial-technological competence and production capacity soon established the Union as the leader of the High Republic formed by the old Sponsored Colonies and the Solarian System.

In 2289 the Congress of the Republic agreed to a new constitution, based on Covenant principles recognizing the right of sentient beings of all races and the sovereign rights of the people of each planet to exercise full control over their internal affairs. Under the moral example of Terra, which again became revered by many as the Mother Planet of the human race, the Republic achieved high standards of conduct toward indigenous alien races. The Contact Service was established in 2293 to safeguard aboriginal and developing peoples from cultural shock and the often ruthless exploitation of some members of the technologically more advanced starcultures. This policy increasingly brought the Republic into friction with the economic imperialism of the Mercantile League and the outright political imperialism of the G.P.R. and the Azuriach Imperium. The name of Terra became synonymous with championship of the oppressed minorities and races of the near galaxy, and anathema to the exploitationists and imperialists of the other human starcultures.

Interstellar war became inevitable. Not only contact with inimical alien races like the Bugs, the Klackons, and the Ranan Horde, but conflict with the starcultures settled from Terra itself forced the Republic to defend itself. But it was populous Terra, with her great industrial capacity and technological supremacy, which had developed the mass of the powerful space and ground forces needed to protect the Republic and the many planetary protectorates under the watchful eye of the Union Contact Service. In the 225 years of the Terran Union, the courage and fighting skill of the elite Union Guard became legendary.

All this is not to minimize the contributions of the 59 other planets of the High Republic, for they too had a major part to play in the history of the starculture. But Terra alone surpassed their combined populations and industrial capacity. Thus, it was one starsystem alone that stands out as the undoubted leader of the mainstream in human evolution into a major starculture, and the enemies of the Republic entertained no doubt as to who the real enemy was - Terra and the Terran Union of the Solarian Planets alone. It was the bastion of Civilization, the champion and the arsenal of free peoples everywhere. Alone, it could stand against all of its enemies combined.

But Terra acquired staunch allies. Not only other human-inhabited worlds appealed to the Terran Union for assistance and support, but numerous alien races as well. The Rauwoof Worlds, caught between the warring G.P.R. and the Azuriach Imperium, became 'friends and valued allies’ of Terra in 2316. The Lords of the MekPurr, hard pressed in the terrible Bug invasions, discovered that not all humans were vicious pelt-hunters when the great BattleFleets of the Guard arrived to relieve Alcyone V in 2328. And in 2395, the embattled StarKingdom of the Blarad welcomed Terran support when the crack squadrons of the Imperial Azuriach StarNavy had shattered the Royal StarFleet in the Battles of Deneb. There were many other minor races, humanoid and pithecine, and others with starkly alien shapes and cultures, who all knew the strength of the Terran Union was arrayed in their defense.