Turgon, 24th Ruling Steward of Gondor
Turgon was the son of Túrin II of Gondor, and the grandfather of Denethor II, the last ruling Steward of Gondor. As with many of the Stewards who tended to be long-lived, thanks to the (albeit thinning) Númenorean blood in their line, both Turgon and his son, Ecthelion, lived to the ripe old age of 98. Turgon ruled as Steward for 39 years. During his many years, he lived through some very turbulent times prior to the War of the Ring, and would have experienced these major events in Gondor and her surrounds:
~ the battles of the Poros between Gondor and the Haradrim when the Oath of Eorl was invoked and the twin sons of Folcwine of Rohan, Folcred and Fastred (only 27 at the time) were killed and the Haudh in Gwanur
burial mound was raised. Turgon was 30 at this time and presumably fought in his father's service, perhaps even at the side of the Rohirric princes.
~ the building of Henneth-Annûn, which occurred in 2901. Turgon's father refortified Cair Andros and ordered the creation of this hidden enclave behind these famous waterfalls for the soldiers of Ithilien, and it continued to be guarded through the War of the Ring.
~ the Fell Winter, which happened in 2911. While the most devastating effects were written about in the Shire, presumably such icy fingers of harsh weather would have extended to the countries further south, though that is conjecture.
Two years prior to Turgon's death, Sauron re-entered Mordor, raised Barad-dûr, and Mount Doom burst into flame. This led to the exodus of the remaining people of Gondor in Ithilien, who presumably relocated to other places in Gondor, perhaps to Minas Tirith or Dol Amroth since those two locations were the most fortified in the region.
Prior to this, however, Steward Turgon had the good fortune and privilege of the then-prince of Rohan serving in his army for around 30 years. Thengel of Rohan, son of Fengel and father to Théoden (who was born in Gondor), left Rohan when he "came to manhood," presumably around age 18. He could have arrived in Gondor in 2922 and served Turgon and his son Ecthelion (18 years Thengel's senior), for around 30 years until Turgon's death in 2953. Interestingly, in that same year Fengel also died, and that was when Thengel was recalled to Rohan.
At Turgon's death, Saruman took over the Gondorian-held but essentially Rohirric property of Isengard. Saruman had been living there since 2759, or 194 years, so several generations of Rohirrim would have been used to the Wizard and his presence in the tower. It is not known how Ecthelion, Turgon's son, took this news, though it could be expected that he was displeased by such a brazen usurping of the fortress. Given the increased peril on his immediate borders, however, Ecthelion probably did not pursue the matter to any great degree.
Sources: The Lord of the Rings,
Appendix A, I, (iv), "Gondor and the Heirs of Anárion." Like most of the other Stewards, Turgon's birthdate is not listed, but it does appear in the "People's of Middle Earth" volume of History of Middle Earth
(which I don't own; I took that info from his short character bio at Henneth-Annun). The information on Thengel and the twin sons of Folcwine is taken from Appendix A, II, "The House of Eorl." Other specific dates of particular events such as the Fell Winter and re-volcanizing of Mount Doom are found in Appendix B, "The Tale of Years."