Karolidis's initial research, during the 1870s and 1880s, was focused on his home region of Cappadocia, with the publication of Kappadokika, a historical and archaeological dissertation on Cappadocia in 1874 and his studies on the city of Comana and the Cappadocian Greek dialect published in 1882 and 1885 respectively.

Although an eminent Orientalist, after his appointment to the University of Athens Karolidis largely neglected the field and instead turned to Greek and general history, in conformity with the chairs he held.
He published 18 books and 38 articles in the period 1893–1908, including his three volume History of the 19th Century, a three volume-work (plus the introductory Introduction) which focuses on Greece, and his unfinished Universal or World History, only four of whose projected ten volumes were completed.
The latter work is of particular importance as it was one of the rare studies on the historical method written in Greek until then.
He is also notable as the editor of the revised edition of Paparrigopoulos' History of the Greek Nation, published in 1902–1903.

The period after the Balkan Wars was not very productive for Karolidis, but after 1922 he produced some of his most famous works, dealing with the post-Byzantine period of Greek history (Ottoman Greece and Modern Greece): the seven-volume Contemporary History (1922–1929) and the History of Greece (1925).
The eighth volume of the Contemporary History was eventually published in 1932, incorporated in the sixth edition of Paparrigopoulos' History of the Greek Nation.
Karolidis's initial research, during the 1870s and 1880s, was focused on his home region of Cappadocia, with the publication of Kappadokika, a historical and archaeological dissertation on Cappadocia in 1874 and his studies on the city of Comana and the Cappadocian Greek dialect published in 1882 and 1885 respectively.
Although an eminent Orientalist, after his appointment to the University of Athens Karolidis largely neglected the field and instead turned to Greek and general history, in conformity with the chairs he held. He published 18 books and 38 articles in the period 1893–1908, including his three volume History of the 19th Century, a three volume-work (plus the introductory Introduction) which focuses on Greece, and his unfinished Universal or World History, only four of whose projected ten volumes were completed. The latter work is of particular importance as it was one of the rare studies on the historical method written in Greek until then. He is also notable as the editor of the revised edition of Paparrigopoulos' History of the Greek Nation, published in 1902–1903.
The period after the Balkan Wars was not very productive for Karolidis, but after 1922 he produced some of his most famous works, dealing with the post-Byzantine period of Greek history (Ottoman Greece and Modern Greece): the seven-volume Contemporary History (1922–1929) and the History of Greece (1925). The eighth volume of the Contemporary History was eventually published in 1932, incorporated in the sixth edition of Paparrigopoulos' History of the Greek Nation.
Pavlos Karolidis