WOW PowerLeveling: A major benefit of the alliance is the ability to create a much larger pledge
Alliance System: Using the alliance system, a savvy Prince or Princess can expand his or her power base and lay siege to castles with WOW PowerLeveling a much larger force than previously possible.
The alliance system allows a high-level Prince or Princess to establish an alliance, or expanded Blood Pledge, after completing a quest to prove one's worth. An alliance can be composed of multiple pledges.
A regular pledge cannot contain more than one Prince, but an alliance pledge may have many royals within it. However, only one Prince or Princess may be the official leader with power.
When two or more pledges form an official alliance, they will become one larger pledge with a common leader and a common alliance pledge emblem.
(Obviously, the group leader and new emblem should be agreed upon by the Princes discussing a merger prior to the alliance being created.)
A major benefit of the alliance is the ability to create a much larger pledge, with multiple sovereigns in it.
A Prince in charge of a regular Blood Pledge has all responsibility for running the pledge. If a Prince joins under an alliance Prince, they forfeit all of their former leadership abilities. They can no longer declare war, accept members into the pledge, or administer the pledge.