Of the early years of the Fourth Age, ending with the passing of King Elessar and the departure of Legolas and Gimli from Middle-earth, an account can be found in the Appendix of The Lord of the Rings. The Chronology below outlines subsequent events only…
170 - Shadow Cult, led by a mysterious figure named Herumor, arises in Umbar
190 - Shadow Cult grows and by this year has a presence in Ithilien
220 - The Shadow Cult's machinations lead to the Breaking of the House of Telcontar with the estrangement of the sons of Eldarion upon his death in this year
225 - The Fall of Umbar. The Haradrim, in league with the corsairs, retake Umbar and drive out the garrisons of the Reunited Kingdom. Cultic agents are suspected of instigating this.
226 - Corsair invasion of Gondor's coasts, supported by Haradrim land assault
227 - Principality of Harondor founded
228 - Orthanc falls to Dunland
229 - Easterlings attack the Reunited Kingdom's garrisons in Rhovanion. They are driven back with great loss on both sides, especially to the Reunited Kingdom's ally, Rohan.
230 - Dunlendings seize Westmarch
355 - Adunabar takes the old Elven retreat of Imladris
356 - Haradrim assault Gondor with Corsair allies.