The Time of Troubles aka. The Arrival, The Godswar or The Avatar Crisis, occurred 121 years ago and was precipitated when the gods Bane & Myrkul, attempted to steal the Tablets of Fate from the overdeity Ao.
Angry at the gods for their habitual pursuit of power and negligence toward their mortal faithful, Lord Ao relegated every god (except for the guardian god Helm, selected to protect the gates to the heavens) to walk among their followers on the earth.
The effects of this edict were drastic - it restricted divine magic (powers granted to a cleric by their patron deity) from functioning unless the cleric was within one mile of their deity's avatar; arcane magic ceased to be regulated by its steward, Mystra & became dangerously unpredictable and the characteristically immortal & aloof deities were now vulnerable (though still devastatingly powerful), dwelling amongst the civilizations of Faerûn.
An obvious and major result, was the widespread cataclysm that affected the continent - chasms opened across the continent, some on seabeds draining them into the Underdark below. Coastlines altered, populations fell, towns & villages shrank in size - portions of the ground 'motes', broke away and rose to float suspended in the air, water sources continued to flow and waterfalls rained down back to the ground.
The Time of Troubles was a time of significant turnover among the gods of Faerun and several deities were "destroyed" during this period:
Bane (greater god of tyranny, strife and hatred) was slain in a climactic battle with the demigod Torm,
Bhaal (god of murder) & Leira (lesser goddess of deception & illusion) were slain by the young mortal Cyric,
Gilgeam (demigod and king of Unther) was slain by Tiamat,
Ibrandul (a lesser god of caverns) was destroyed by Shar,
Moander (demigod of decay) was slain by the mortal Finder Wyvernspur,
Myrkul (greater god of the dead) was killed in a duel with Midnight, a mortal woman wielding the powers of Mystra,
Mystra (greater goddess of magic and among the most powerful of the gods) was in turn destroyed, when she attempted to bypass Helm at the Celestial Staircase,
Ramman (Untheric lesser god of war and storms) was slain by Hoar,
Tiamat was slain by Gilgeam.
However, death is anything but permanent in the Forgotten Realms and many of these deities have in some way circumvented their own destruction:
After Bane's death, his portfolio was divided among the newly anointed god Cyric and Bane's own half-demonic son Iyachtu Xvim. Upon the death of one of the greatest forces of evil in existence, all of Faerûn breathed a sigh of relief; however, 14 years later, Bane was resurrected, destroying Iyachtu Xvim and reestablishing his church,
Myrkul infused the sinister artifact the Crown of Horns, with the remnants of his essence and teleported it away. While its location is unknown, the semi-sentient artifact is presumably fomenting a plan for Myrkul's resurrection,
Bhaal had foreseen his own death and had populated Faerûn with his progeny, the Bhaalspawn, in a bid to resurrect himself,
Tiamat's essence was divided among three dragons, the red Tchazzar, the blue Gestaniius and the green Skuthosiin; Tchazzar consumed the other two and was subsumed by Tiamat; The Dragon Queen then destroyed Gilgeam later in the Godswar,
Torm (demigod and patron deity of paladins) was annihilated by Bane with his dying breath - but was later resurrected by Ao, because he died fulfilling the obligations of his portfolio,
Waukeen (lesser goddess of wealth) attempted to reclaim her divinity during the Time of Troubles, leaving her portfolio in the care of Lliira, but was imprisoned in the Argent Palace, enslaved to the demon prince Graz’zt; she was freed from her prison 13 years later, by a band of adventurers and has resumed her place in the heavens,
Furthermore, a selection of mortals were chosen by Lord Ao to ascend to the heavens, to fill the void left by those deities who died:
Cyric, a petty & sadistic mercenary, slew Bhaal with the sword Godsbane (actually the god Mask in disguise) and Kelemvor (a sullen adventurer & companion of his); but Kelemvor's soul was hidden by Mask and unintentionally gained the portfolio of death, by defeating Cyric with the help of Godsbane (Mask in the form of a sword).
[He has since striven to change the horrifying image of death promoted by his predecessors].
After her death, the goddess Mystra entrusted her essence to the young mage Midnight, who ascended after the Time of Troubles as the new Mystra.
The exceptional adventurer, Finder Wyvernspur, absorbed and adapted Moander's portfolio and is now the patron of the cycle of life.
