Uchtred or Uhtred, called the Bold, (d. 1016) was the ealdorman of all Northumbria from 1006 to 1016, when he was assassinated. He was the son of Waltheof I, ealdorman of Bamburgh, whose ancient family had ruled from the castle of Bamburgh on the Northumbrian coast.
Uchtred was the ealdorman of all Northumbria for more than 20 years.
It's definitely incorrect because he only held the position for 10 years. It's difficult because the system seems unable to make these types of calculations and comparisons for some reason.
( z1 have-org-role :ARG0 ( z2 person :name ( z3 name :op "Uchtred" ) ) :ARG1 ( z4 country-region :name ( z5 name :op "Northumbria" ) :mod ( z6 all ) ) :ARG2 ( z7 ealdorman ) :duration ( z8 more-than :op ( z9 temporal-quantity :quant 20 :unit ( z10 year ) ) ) )