While out on a supply run, Rick and Daryl crossed paths with Jesus from The Hilltop, a neighboring colony, and after learning The Hilltop was being threatened by another faction — The Saviors — Alexandria and The Hilltop formed an alliance.
Though Alexandria has yet to make contact with The Kingdom, the colony does already have trading relations with The Hilltop.
Not long after The Hilltop established itself and began harvesting its plentiful crop, The Saviors arrived, demanding half of everything The Hilltop grew in return for protection.
Alexandria would eliminate The Saviors, and in return The Hilltop would give them half of their supplies.