You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
In OTL, when Alfonso I of Aragon died childless, the union between Aragon and Navarre/Pamplona ceased. So, what if, likely due to a different and earlier marriage, Alfonso produced heirs and Aragon and Navarre continued to be united under one king?