This is the subsector at the founding of the Third Imperium, the time period of Marc Miller's Traveller (T4). To the best of my knowledge, the Spinward Marches was never presented in T4, so the information here is purely speculative. If there is published information about the Spinward Marches as it existed in year 0, please email me.
The time of the founding of the Third Imperium is a good time for the Daryens. The Zhodani, while annoying, are still far away. The Sacnoth Dominate has imploded, making the Sword Worlds a non-threat at this time.
When the Sword Worlds unified as the Sacnoth Dominate, the Daryen Group was completely unprepared. As a counter, they quickly began building some military bases at Mire, Zbume, and the newly annexed Nosea. Even after the implosion of the Dominate, the Daryens decided to continue with their higher level of readiness. They eventually added bases at Laberv and Yelim, and connected them with a communications network. This network eventually transformed into the Darrian Confederation's X-boat network.
The Daryen Group is still primarily focused on
their already established worlds, leaving some worthwhile candidates dormant
for the moment.
Zamine is effectively a client state of the Daryen Group, but is current too far away to be formally included. While not space capable themselves, they still see low, but regular traffic from the Daryen Group via Terant 340.
Terant 340 itself is unpopulated. There is a small station orbiting the major gas giant that supports the traffic to and from Zamine. While not technically a military base, it is run by the Daryen Navy.
494-908 had been colonized by the pre-Maghiz Daryens. It had an untainted atmosphere, moderate water coverage and fairly tame wildlife. It was a hospitable world. When recontacted by Mire, the recontact team found a sterilized planet contaminated by exceptionally high levels of radiation. Nothing was ever explained as to what happened. Instead, the planet been interdicted by the Daryen Navy and turned into a naval training ground.
Entrope was originally colonized by ethnic Daryens, but they are eagerly pursuing their own course. It is taking advantage of its distance from the Daryen Group and the disarray of the Sword Worlds to carve out a little niche for itself. Winston has been extensive colonized from Entrope, and token bases have been established on Anselhome and Torment. Winston has seen significant immigration because of its excellent planetary environment, especially as compared to Entrope itself.