▁the ▁emp ire ▁was ▁about ▁ 2 , 6 5 5 , 5 6 4 . 7 6   km 2 ▁( 1 , 0 2 5 , 3 1 9   sq   mi ) ▁ ▁India ▁ ▁Den mark – N or way ▁maintained ▁numerous ▁colon ies ▁from ▁the ▁ 1 7 th ▁to ▁ 1 9 th ▁centuries ▁over ▁various ▁parts ▁around ▁India . ▁Col on ies ▁included ▁the ▁town ▁of ▁T ran qu eb ar ▁and ▁Ser amp ore . ▁The ▁last ▁towns ▁it ▁had ▁control ▁over ▁were ▁sold ▁to ▁the ▁United ▁Kingdom ▁in ▁ 1 8 4 5 . ▁Rights ▁in ▁the ▁Nic obar ▁Islands ▁were ▁sold ▁in ▁ 1 8 6 9 . ▁ ▁Car ib bean ▁ ▁Cent red ▁on ▁the ▁Virgin ▁Islands , ▁Den mark – N or way ▁established ▁the ▁Dan ish ▁West ▁Ind ies . ▁This ▁col ony ▁was ▁one ▁of ▁the ▁longest - l ived ▁of ▁Den mark , ▁until ▁it ▁was ▁sold ▁to ▁the ▁United ▁States ▁in ▁ 1 9 1 7 . ▁It ▁became ▁the ▁U . S . ▁Virgin ▁Islands . ▁ ▁West ▁Africa ▁ ▁In ▁the ▁Gold ▁Coast ▁region ▁of ▁West ▁Africa , ▁Den mark – N or way ▁also ▁over ▁time ▁had ▁control ▁over ▁various ▁colon ies ▁and ▁for ts . ▁The ▁last ▁remaining ▁for ts ▁were ▁sold ▁to ▁the ▁United ▁Kingdom ▁in ▁ 1 8 5 0 . ▁ ▁History ▁ ▁Orig ins ▁of ▁the ▁Union ▁ ▁The ▁three ▁kingdom s ▁then ▁un ited ▁in ▁the