Fictional Series And Future Histories

Stages of Fiction
(i) A single story about a fictitious character.
(ii) A series of stories about a single character.
(iii) A series featuring several co-existing characters, thus presenting alternative perspectives on a fictitious environment.
(iv) A series following several generations of characters.

In futuristic sf, (iv) is a "future history," a series with installments set in successive periods of a fictitious history. Any newly published installment of a future history may either present new information about an already established period or introduce a different period, whether earlier or later.

Thus, Robert Heinlein's Future History includes several stories set during an early period of Lunar and interplanetary colonization but also other works set after a later cessation of space travel. Poul Anderson's History of Technic Civilization grew from a single story about one fictitious character.

(i) "Tiger by the Tail" (Jan, 1951), about Dominic Flandry (see also here).
(ii) Subsequent works featuring Flandry, this series eventually totaling thirteen.
(iii) Two other works set during Flandry's lifetime.
(iv) Twenty four works set in several pre-Flandry periods and four works set in different post-Flandry periods.

Thus, a series of type (iv) incorporates series of types (ii) and (iii). In fact, sixteen pre-Flandry works are set during the lifetime of Nicholas van Rijn.

Thus, the parts of the History that are most future historical are at the beginning, middle and end.

The Opening Three Stories:
interplanetary exploration in the 21st century;
interstellar exploration in the 22nd century;
planetary exploration in the 24th century.

The Technic Civilization Saga, Vol III: Rise Of The Terran Empire
A concluding novel about van Rijn and his contemporaries in the 25th century.
Two incidents during the colonization of Avalon in the 26th century.
The founding of the Terran Empire about 2700.
An incident involving the Terran Empire in the 28th century.
A novel about the Terran Imperial War on Avalon in the 29th century.

The Concluding Four Works
Incidents in 3600, 3900, 4000 and 7100.

(However, for an alternative perspective on the Chronology, see here.)