Who was older, 이백년 or 이조년?

ANSWER: 이백년

Lee Jo-nyeon (이조년 - 李兆年) lived from 1269 to 1343 and was a civil servant (문신) during the time of the Goryeo Kingdom (918 - 1392). He was also a poet (시인) and a literary man (문인) who wrote the well-known poem (시조) that starts with the line "梨花月白三更天(이화월백삼경천)." The line translates as follows: "The pear blossoms (梨花) [and] moon (月) are white (白) [against] the midnight (三更) sky (天)."

Mr. Lee was the youngest of five brothers, and his given name literally means "a trillion (조 兆) years (년 年). Here are the given names of his four elder brothers, listed from eldest to youngest:

1. 백년 (百年) - a hundred (百) years (年)
2. 천년 (千年) - a thousand (千) years (年)
3. 만년 (萬年) - ten thousand (萬) years (年)
4. 억년 (億年) - a hundred million (億) years (年)

You can read a Korean-language article on Lee Jo-nyeon HERE.

Here is my translation of Mr. Lee's poem:

梨(이)花(화)月(월)白(백)三(삼)更(경)天(천)
The pear (梨) blossoms (花) [and] moon (月) are white (白) [against] the midnight (三更) sky (天).

啼(제)血(혈)聲(성)聲(성)怨(원)杜(두)鵑(견)

Crying (啼) sad tears (血) [and] making (聲) noise (聲), the resentful (怨) cuckoo (杜鵑).

盡(진)覺(각)多(다)情(정)原(원)是(시)病(병)

Wide (盡) awakeness (覺) [and] many (多) emotions (情) cause (原) this (是) anxiety (病).

不(불)關(관)人(인)事(사)不(불)成(성)眠(면)

Unrelated (不關) human affairs (人事) do not (不) produce (成) sleep (眠).

This guy reminds me of me, except instead of a cuckoo, I have a neighbor's dog.
 
I do not know why, but in "The Columbia Anthology of Traditional Korean Poetry," Peter H. Lee, my former Korean literature professor at the University of Hawaii, translated the poem as follows:

The moon is white on pear blossoms,

and the Milky Way tells the third watch.

A cuckoo would not know

the intent of a branch of spring.

Too much awareness is a sickness,

it keeps me awake all night. 

Unfortunately, the "The Columbia Anthology of Traditional Korean Poetry" does not show the original Chinese, so there is possibly another version of the poem I have not seen. By the way, I do not like reading old Chinese and Korean poetry unless they also include the original Chinese. I like having the option of being able to interpret the poems myself.