From 1945 to 1963 he was with Madhya Pradesh Educational Service and taught at the Government Colleges at Nagpur, Jabalpur, and Bhopal.
"[8] The controversy surrounding these events is reflected in the theme of the discourses of his books which allegedly describe Muslims as foreigners, destructive barbarians and immoral degenerates,[9] Lal himself disputes these allegations, citing, in turn, that the ICHR has always been dominated by historians with a 'strong leftist bias' and that the current controversy is "merely the outcome of an exaggerated sense of pique on the part of the excluded Left wing".
[11] Historian Jeremy Black in his book Contesting History: Narratives of Public History (2014), referenced his book The Muslim Slave System in Medieval India as a "good modern work"; he also comments that K. S. Lal " is regarded as right-wing by Indian Muslim Marxist scholars".
[17] K. S. Lal wrote a reply to Irfan Habib's criticism in 1979 in his book Bias in Indian Historiography (1979) and Theory and Practice of Muslim State in India (1999).
[18] K. S. Lal wrote a rebuttal to Jackson's criticism in his book Theory and Practice of Muslim State in India.
[19] Avril A. Powell of University of London said the book was "propaganda" that was especially dangerous as it was written by a historian as esteemed as Lal.