At last I have managed to talk Strider into giving me the full account of Gil-galad and the Last alliance between Elves and Men that caused the dark Lord's fall. Here I am writing down exactly what he said to keep it in mind. I only hope he wasn't making fun of me; I'm merely a poor little ignorant hobbit and don't know any better. So this is what Strider told me:
Millennia ago, upon a time when there was no Grubb of Michel-Delving Watch to measure it, Ereinion Gil-galad, last High King of the Noldor (Nothing Surpasses A Noldor Work, by the way), joined forces with Elendil of Númenor (All That Is Good Comes From The West) to do battle against Sauron of Mordor, the Dark Lord, darker even than Lothlórien's High Quality Ebony. So these armies approached the Fire-Resistant, Unbreakable Morannon, the gate of Mordor, where Sauron's servants were busily pouring out Orodruin's Best Vapours, and broke it (which proves you should never believe a commercial). Soon after, they started the long, grievous siege of Barad-dûr.
So seven years passed. Anárion, the younger son of Elendil, was hit on the head by a heavy rock, but because he wore his Durasteel Super Battle Helm, he only had a slight headache after it. Many heroic deeds were done then, among them the discovery of Isildur's Portable Hair Washing Basin for Travels, something especially the Elves enjoyed, not being able to use Sauron's private Best Dread-Bath Design Mordorian Bathtub. One of these happy Elves was Elrond, the brave herald of Gil-galad. [Elrond was proud to say that he was a very clean Elf (although he was only half-elven actually, but Half-Elven Lasts Longer, as his twin brother and he had used to assure themselves when they had still been children). He washed his silky dark hair with Vána of the Valar's Glamour Shampoo and brushed it with Varda's Wondrous Hair Care Brush for Neat and Clever Elves. He also washed his pointy ears, of course (Nienna's Soft Cleaning Balm for Tender Elf-Ears).]
Now Elrond and Isildur were companions in arms, and they usually went through all of their adventures together. They even destroyed the spider webs of darkness in Cirith Ungol, woven by Shelob Spinning Ltd., and they raided the orc colonies of Udûn (Producers of Fine Battle Orcs – The Perfect Orc For Every Purpose! – since 1151). As finally the seventh year of the siege began, they had both grown weary from it al. Isildur missed the sea (created by Ulmo & Co. Water World Engineering, as it was common knowledge in Númenor) and the wide forests of Eriador (with thanks to Yavanna's Olvar Department – Makers of All Growing Things in Middle-earth). And he decided that something had to happen. So he took Elrond along to his Dreamland Westernesse Tent, where they could discuss the matter. After a bit of rolling around on Isildur's Royal Highness Blankets (Sleep like A God In Valinor!) and scratching his pointy ears, Elrond finally came up with a great idea…
The next day, after Gil-galad's great battle horn was sounded (sponsored by Círdan & Co. – Ships that never stray on their Course), Elrond dashed through the fray, right towards Sauron, who was just celebrating his impressive appearance (clad in Balchoth Horror Battle Armour, of course), and waved an Original Magic Ring made by Celebrimbor the Uncanny before his face. Sauron, famous for owning Middle-earth's Largest Collection of Rings of Power, wanted to have it immediately. Too bad Gil-galad and Elendil wanted it too. If not for Saeros's Best Elvish Running Shoes, poor Elrond would have been done for. Instead, Gil-galad and Elendil started quarrelling with Sauron. They fought before the gates of Barad-dûr until Aiglos and Narsil, spear and sword of the two allies, broke (a pity, they had both been Telchar's Miraculous Wonder Smithy Works) and they themselves had to be taken to Celebrían's Very Special Recovering Department by Gwaihir's Eagle Airlines. This was the point when Elrond returned and smote Sauron down with a gigantic drinking bottle (Always Elfy-Cola!), and Isildur sprang to his side with his razor-sharp Heavenly Combat Aid Pocket Knife and cut from the Dark Lord's hand the highly dangerous device he had fixed there: The Chocolate of Doom (One Chocolate to rule them all, to make them come up, One Chocolate to bring them all and make them sick at the stomach!).
So ended the Second Age, and so the Third Age of the World began. History became legend. Legend became myth. And many things that should not be forgotten… were lost.
But the Chocolate of Doom was still there, betraying all its "users" to a terrible hangover (as can be seen in the case of Gollum, a long-time eater), until the world was rid from it by Frodo Baggins, a brave young hobbit from the Shire (Where Gandalf spends his Holidays – he knows why!). But this is an entirely different story and shall be told at a different time and when smoking a different pipeful of Longbottom Leaf – Most Enjoyable Way To Ruin Your Lungs.