Daniel 11:6

And in the end of years they shall join themselves together; for the king’s daughter of the south shall come to the king of the north to make an agreement: but she shall not retain the power of the arm; neither shall he stand, nor his arm: but she shall be given up, and they that brought her, and he that begat her, and he that strengthened her in these times.

Cross-references

Daniel 11:7 directly follows with the retaliation of the South king's brother, forming the immediate next event after the alliance.

Daniel 11:13 picks up the North king's later military buildup, continuing the conflict after the alliance described in 11:6.

Daniel 11:15 details the North king's siege of a fortified city, a later campaign in the same ongoing war.

Daniel 2:21 states God sets up and deposes kings — the theological principle underlying why this alliance fails.