Unification of Houses is the creation of a lasting bond between two House lines, through which decisions and memory begin to pass beyond ordinary neighbourly relations. A shared courtyard, marriage, or a joined wall does not yet constitute unification. It begins when one House answers an obligation that arose in the other.
A Third Order
Unification does not combine two complete structures. Even under an equal agreement, a third order emerges: some former rules remain, some become incompatible, and some decisions acquire meaning for the first time only when taken together.
Unifying houses was always considered a troubling undertaking, for in neither was it known beforehand which of the two would lead and which would follow; and there were cases in which the younger house outlived the older, and cases to the contrary, and cases in which both houses that had agreed to unite were, five winters later, no longer one or the other, but became a third—and this third no longer remembered the names of those who had conceived the unification.
From the Courtyard to the Inner Circle
An external joining opens a passage and a shared way of life. A shared courtyard allows the Houses to hold the same events from different sides. A union through marriage binds future obligations but preserves two lines. True unification begins only when the inner circles are brought into communication.
The transition is made through one kind of decision at a time: first the Houses jointly receive a guest or take responsibility for a child. If both Houses hold the outcome without struggling for primacy, the bond is expanded. Opening all circles at once is considered a sign of coercion or desperation.
Why Take the Risk
Unification is used to save a line with no successor, join a divided school of craft, or create a common House after a long period as neighbours. Political alliances also use the practice: a single strong knot of memory can sustain an agreement longer than human generations.
The well-known joining of the Copper Courtyard and the House at the Quiet Arch began over water. Seven years later, the first House began to remember the second's debts, and the second remembered the first's guests. The union was recognised as successful only after a child of both lines was able to close the common circle from either courtyard.
Loss of the Original Houses
The main risk is not struggle, but success without measure. The new bond may draw in all decisions, depriving the original Houses of the ability to answer separately. Undoing the unification would then mean not separating what existed before, but tearing apart the third House that has already arisen.
Incompatibility gives rise to false inheritance, Shift, and Contamination: one House mistakes another's memory for its own obligation. Therefore, before the work begins, they name the things and rooms that will never become shared. If the first of these boundaries is breached, the unification is halted even when all other signs are favourable.