Sony's love for big screens goes all the way back to 2013 and the 6.4" Xperia Z Ultra, which was followed by a phablet in every generation since. Some four years later we have the Xperia XA1 Ultra at our doorstep, all 6 inches of it.
Source: http://www.gsmarena.com/sony_xperia_xa1_ultra-review-1618.php