You can unlock this as early as DNA Sequence 11. After completing the memory ‘Practice Makes Perfect’ in DNA Sequence 3, you are able to place the feathers you’ve collected in a chest on your mother’s dresser in Monteriggioni. Once you have placed all 100 feathers in the chest, there will be a short cutscene with Ezio hugging to his mother and the Auditore cape will be unlocked.
Note: When you’ve deposited 50 feathers, you will unlock the ‘Condottiero War Hammer’ to purchase at Monteriggioni’s blacksmith for 35,000f (less if you’ve upgraded the Blacksmith).
Once you have control again, to wear the cape, pause your game and navigate to Inventory > Outfits > Auditore Cape and press to equip it. The cape gives you instant Notoriety in any city you visit and you can’t lower it by tearing down posters or bribing Heralds until you switch to another cape.
Now, to unlock this achievement, you need to fast travel to every city (located by the icon on the map). Go to the fast travel station outside the gates of Monteriggioni and select another city. When you appear in that city, just repeat the process. Once you have selected all four (Tuscany, Forli, Venice and Florence [go here last]), you must also visit the Apennine Mountain region where you met Leonardo and had that carriage chase before arriving in Forli during DNA Sequence 6. Fast travel to the ‘San Marco - East Gate’ in Florence (since that is the closest station to the Mountains), walk out of the gates and get on a horse. Take the northernmost path to travel to the mountains. The achievement will unlock as the game is loading.
Refer to “In Memory of Petruccio” for a video showing the locations of all 100 feathers.
The easiest way to do this would be probably going to a travel station, change your cape before you go in, and then go from city to city by the travel station. Don't know if this works but you can give it a try.
The cape is unlocked by collecting all 100 feathers that are scattered throughout the game. Once all have been found and taken to the chest is Monteriggioni then you need to equip the cape and go to every city and the mountain region.
I've went to all travel stations with the cape on, and went to florence and rode a horse into the mountains. and no achievment. do you have to ride all the way through the mountains or can u just enter and leave?
best site for feather locations was msxbox-world.com had all locations broken down by individual cities where you can click feather so reveal a screenshot and map point. but best of all you can click complete when u get it and it x's that one out so its really easy did all 100 feathers in under 2 hours
Here is an excellent site for the feathers and glyphs.... http://achievementhunter.com/games/guides/ac2/index.php You can select wavy one and it brings up a YouTube video of how to Get to it in you need to. There's also a list at the bottom that you click to hide the ones you have picked up in each area
Oh and the cape is unlocked by finding all the feathers, NOT by completing the game.
Well spotted #2, #4 and a few others, because I forgot to go to the mountains, till later. This is the trickest place, as it doesn't have a travel stations, so I got this place last. But all in all, it's a great chevo. :-)