DARU ‘L-ISLAM دار الاسلام
“Land of Islam.” According to the Raddu ‘l Mukhtar, vol iii p. 391, it is a country in which the edicts of Islam are fully promulgated.
In a state brought under Muslims, all those who do not embrace the faith are placed under certain disabilities. They can worship God according to their own customs provided they are not idolaters; but it must be done without any ostentation and whilst churches and synagogues may be repaired, no new place of worship can be erected. “The construction of churches and synagogues in Muslim territory is unlawful, this being forbidden in the Traditions; but if the places of worship belonging to Jews, or Christians, be destroyed, or fall into decay, they are at liberty to repair them because buildings cannot endure forever.”
Idol templet must br destroyed, and idolatry suppressed by force in all countries ruled according to strict Muslim law. (Hidiyah, vol ii, p. 219)
For further particulars, see article DARU ‘L-HARB

Based on Hughes, Dictionary of Islam