The House of Knowledge lets you discover and upgrade Fields of Knowledge. These give Bonuses to all your League Members. You can only upgrade ONE Field of Knowledge at a time, and the Knowledge Level cannot be downgraded by attacks. Note that only League Marshals and authorized League Members can upgrade Fields of Knowledge.
The House of Knowledge has three tabs:
1. Info. In this tab you can see the Bonuses provided by the House of Knowledge. Upgrade the Building to get more Bonuses.
2. Mara’s Knowledge. This shows the Bonuses Mara’s Fields of Knowledge provide and their current Level. To upgrade Mara's Knowledge, you need special League Resources: Ambrosia, Amber, and Taenite. To upgrade it to the highest Levels, you'll also need Compendiums.
3. Weor’s Knowledge. This shows the Bonuses Weor's Fields of Knowledge provide, their current Level, and the number of Tomes owned by your League. To upgrade Weor's Knowledge, you will require Tomes.