Assassin's Creed Syndicate

To get this trophy that’s called “A Life in Letters”, you must collect 12 Royal Correspondence letters located in the Westminster District.

There is actually no map that you can buy that will reveal all the locations of the letters, so you will have to use Eagle Vision and search for these letters all over Westminster. Thankfully, there are video guides aplenty on YouTube that will show you all the locations. I’ve included a video from the PowerPyx’s channel that shows you where exactly you can find them.

One tip that I can also provide is to look up the encyclopedia option in the menu, then click on Royal Correspondence Letters option and do a comparison to see which ones you have or don’t have. The ones that you don’t have are the ones that are missing from the map, so use the video I posted in this solution to help you find the one that’s missing.

Once you collect all 12 letters, the trophy will unlock and I believe an Emerald Cloak is unlocked for Evie that you can purchase for $6,000 dollars.

Good luck and happy hunting!