215 ILCS 5/121-1
The purpose of this Article is to subject certain insurers to the jurisdiction of the Director of Insurance and the courts of this State in suits by or on behalf of the State. The General Assembly declares that it is concerned with the protection of residents of this State against acts by insurers not authorized to do an insurance business in this State, by the maintenance of fair and honest insurance markets, by protecting authorized insurers which are subject to regulation from unfair competition by unauthorized insurers, and by protecting against the evasion of the insurance regulatory laws of this State. In furtherance of this State interest, the General Assembly in this Article provides methods for substituted service of process upon such insurers in any proceeding, suit or action in any court and substituted service of any notice, order, pleading or process upon such insurers in any proceeding by the Director of Insurance to enforce or effect full compliance with the insurance laws of this State. In so doing, the State exercises its powers to protect its residents and to define what constitutes transacting an insurance business in this State, and also exercises powers and privileges available to this State under Public Law 79-15, 79th Congress of the United States, Chapter 20, 1st Sess., S. 340, 59 Stat. 33; 15 U.S.C. ##1011 through 1015, as amended, which declares that the business of insurance and every person engaged therein shall be subject to the laws of the several states.
215 ILCS 5/121-1