Adding guilds to Alliance?

Who needs to be online to add a new guild to an alliance? Just the alliance leader? Or the guild leader from all the participating guilds?

I found information that leads me to believe both are true...

Pretty sure you need the alliance leader + the guild leader of the guild you're adding o_o

Haven't done anything with alliance since my guild alliance is dead now that 7/8 of all the people are gone and quit/got hacked. So it may have changed since like 3-4 months ago