158 years!

[Goldnagger]

You should learn math(s?) again

[Asplundh]

You can say a world is conquered when there is no credible threat to the strongest player/guild/alliance.

[xSmith&WessonX]

I think it's best to think in terms of regions rather then whole worlds. And is what you need to calculate is the number of scholarships it would take. A few cities a day isn't that hard until you start running out of scholars. And that's just barbarian once you add troops into the equation and enemy troops it's a hard task for anyone.

So how long would it take to conquer a region by yourself? I would think once you reach that size you need no guild, just for chat and companions/mates.

[xSmith&WessonX]

You can actually grid out a region into sectors. Take one sector at time. As people stop playing absorb the cities. The game takes a long time. If you think long term in year/s its easier to understand the math and why some people play the way they do. It even explains big alliances. It's like survivor. Everyone is their own nation/player and your best interest should come first. What's best for you is best for your guild.