Image from Steve Bowers

The sentient ship 'Fortunate Cloud' decelerates into orbit around To'ul'h Prime, prior to first contact with the intelligent species there

First Order (Terragen Sphere)

• Backyarders, 5th century AT.
• Technocalypse, 6th century AT
• Great Expulsion 622 AT
• First Federation, 946 AT
• The first Singularity (the attainment of the First Toposophic level) (2nd & following toposophics with diminishing direct impact) on ordinary sophonts. More here.
• Version War c. 4450 - 4653 AT
• Earliest distinct nonhuman or posthuman Terragen cultures (subsequent events are second or third order)

Second Order (Regional)

• Negentropism: First Promulgation of the Precepts, 1965 AT
• Solarism: First Interface, 2014 AT
• NoCoZo: Non-Coercion Agreement 1450 AT
• Sophic League: foundation 2345 AT; also important was the Reformulation of 2752 AT
• Metasoft: founded 22nd century AT, vec takeover 2344 AT, creation of the Version Tree 2582 AT
• Keterism: founded at Ain Soph Aur 1788 AT
• Verifex event: 7434 AT
• Oracle War 10480 AT
• Carina Rush beginning 6601 AT
• Contact with the Muuh, an ancient race with venerable technology
• Contact with the Meistersingers, a race seemingly in contact with several other galactic cultures
• First provolves, and AIs, before they developed their own cultures
• Contact with the To'ul'h (subsequent contacts with lower tech xenosophonts are 3rd order)
• First Interstellar colonies (particularly Nova and Penglai, and others which went on to found colonies of their own)

Third Order (niche effects or very local effects)

• Provolution/design of any major clade or a minor exotic clade
• Invention of the Worldhouse.
• First Bishop Rings.
• Defeat of the Conver Ambi.
• Contact with any lower tech xenosophonts (i.e. Paulans)

• Bishop Ring
• Conver Ambi
• First Contact
• Nova Terra
• Novelty Node - Text by Stephen Inniss
  In memetics, a region or time of particular memetic influence, one that generates new concepts, philosophies and fashions that influence a broad region and may have effects lasting for decades, centuries, or even millennia. A number of such nodes have been or are presently active within the Terragen sphere. Some of these are associated with full-blown Renaissance Events.
  
• Penglai
• Renaissance Event
• Version War