Portuguese forces overthrow the Jaffna Kingdom, ending independent Tamil monarchical rule in the North.

British occupation begins; the Tamil and Sinhala nations remain under distinct administrative units initially.

The British unify the entire island into a single centralized administrative unit, submerging Tamil sovereignty.

Introduction of universal franchise. Tamil leaders warn that majority rule will result in permanent Sinhala domination.

Power is transferred to a Sinhala-dominated state. The Lion Flag is adopted despite intense Tamil opposition to its majoritarian symbols.

Sinhala is made the sole official language, excluding Tamil from public administration.

Triggers the Gal Oya Pogrom, the first major post-independence ethnic violence.

State-wide anti-Tamil violence breaks out following the failure of political agreements and language protests.

An agreement for regional councils is signed but quickly abrogated by the government due to Sinhalese nationalist pressure.

A massive civil disobedience campaign in the North leads to the first military occupation of the Jaffna peninsula.

Political pacts promising limited Tamil rights are abandoned or not implemented.

The country is renamed Sri Lanka; Buddhism is given "foremost place." Tamils reject the constitution and burn it in protest.

Section 29 (minority protections) is permanently abolished.

The TULF formally calls for the restoration of a sovereign, secular state of Tamil Eelam.

Shift from seeking federalism to demanding secession.

Executive presidency and unitary state further entrenched.

State security forces burn the Jaffna Public Library, destroying over 95,000 irreplaceable Tamil books and manuscripts.

Tamil groups articulate the Four Cardinal Principles: Nationhood, Homeland, Self-Determination, and Citizenship.

Thimphu Declaration

1. Shift from Secession to Framework: Vaddukoddai Resolution explicitly demanded a "Free, Sovereign, Secular, Socialist State of Tamil Eelam." Thimphu Principles provided the "necessary framework" for any rational dialogue on autonomy.
2. Unified Negotiating Platform: For the first time, all major Tamil political and militant groups (TULF, LTTE, EPRLF, EROS, PLOTE, and TELO) agreed on a single set of overarching principles to define their joint aspirations in an international setting.
3. Thimphu Declaration provided the basis for an alternative solution to an independent state, signaling that if these four cardinal principles were met, the Tamils might consider alternatives to full separation.
4. Internationalisation: By presenting these principles during peace talks in Bhutan facilitated by India, the Thimphu Declaration elevated the demands of the Vaddukoddai Resolution from a domestic political mandate into a recognised international conflict-resolution framework.

Indian military operations in the North-East; heavy civilian suffering.

The IPKF withdraws and Eelam War II begins, characterized by civilian massacres and a state blockade of the North.

Following the collapse of peace talks, major military offensives lead to the displacement of the entire population of Jaffna.

A Norwegian-brokered ceasefire begins, recognizing the LTTE as a negotiating party for the first time.

Large-scale hostilities resume at Mavil Aru, marking the beginning of the final phase of the war.

The Sri Lankan government officially abrogates the ceasefire agreement and launches an all-out military offensive.