Please note:
The correct idioms are:
X date Y at.......
--OR--
Y is dated by X at.....
Both forms are correct. There is no problem with "dated by".
The trap is thatthere is no "at" in the non-underlined part.
The adopted use of trained fighter horses, which some historians date during early Ottoman rule, was a critical element to the expansion of the Ottoman Empire.
(A) The adopted use of trained fighter horses, which some historians date
Wrong. "which" is
...
The correct idioms are:
X date Y at.......
--OR--
Y is dated by X at.....
Both forms are correct. There is no problem with "dated by".
The trap is thatthere is no "at" in the non-underlined part.
The adopted use of trained fighter horses, which some historians date during early Ottoman rule, was a critical element to the expansion of the Ottoman Empire.
(A) The adopted use of trained fighter horses, which some historians date
Wrong. "which" is
...