Fourth Republic — the Boko Haram era (1999–present) — Borno State

Shari'a adoption in Borno (June 2000) — Governor Mala Kachalla, then Ali Modu Sheriff, formally extend Shari'a criminal code to the state; Hisbah established. Pattern: religious-political ordering.
Founding of Boko Haram (2002) — Muhammad Yusuf founds Jamā'at Ahl as-Sunnah lid-Da'wah wa'l-Jihād at the Ibn Taymiyyah Mosque, Maiduguri, drawing on disaffected Almajiri youth; sect briefly relocates to "Afghanistan" camp in Kanama (Yobe) 2003–2004.Northern Abandonment Cycle
Boko Haram uprising (26–30 July 2009) — five-day battle in Maiduguri; Nigerian Army shells the Markas (sect headquarters) at Railway Quarters; c. 800 killed, including Yusuf executed in police custody outside the Shehu's palace 30 July 2009. Pattern: state violence + religious-political conflict.Northern Abandonment Cycle
2010–2014 — bombings, prison breaks, mass-casualty attacks — Bauchi Prison break (Sept 2010); Police HQ Abuja and UN House bombings (2011); twin suicide bombings at St Theresa Madalla (Christmas Day 2011); the assault on Giwa Barracks Maiduguri (14 Mar 2014); Buni Yadi College attack (Feb 2014); Chibok schoolgirls abduction (14–15 Apr 2014 — 276 girls, Borno border with Adamawa, technically Chibok LGA Borno).Northern Abandonment Cycle
State of emergency (14 May 2013 – Nov 2014) — Jonathan declares emergency over Borno, Yobe and Adamawa; Operation BOYONA and later Operation LAFIYA DOLE (2015–) headquartered in Maiduguri.
Caliphate phase (Aug 2014 – Mar 2015) — Abubakar Shekau declares an "Islamic State in West Africa" from Gwoza; sect controls 20+ LGAs across northern Borno (Bama, Gwoza, Konduga, Marte, Abadam, Kukawa, Damboa, Kala-Balge, Mafa, Monguno, Magumeri, Mobbar, Guzamala, Nganzai). Nigerian Army with Chadian and Cameroonian support reclaims towns Jan–Mar 2015.Northern Abandonment Cycle
ISWAP split (Aug 2016) — Abu Musab al-Barnawi (Yusuf's son) splits from Shekau; ISWAP consolidates in the Lake Chad islands (Kukawa, Marte, Abadam, Guzamala), Shekau's JAS retreats to Sambisa Forest.Northern Abandonment Cycle
Civilian-JTF (Yan Gora) — founded June 2013 in Maiduguri's Hausari ward by Baba Lawan Jafar; ~26,000 vigilantes by 2015; central to clearing Maiduguri but with documented extra-judicial killings.Impunity Loop
Mass-atrocity ledger (selected) — Baga massacre (3–7 Jan 2015, Multinational Joint Task Force base overrun, ~2,000 killed per Amnesty), Kukawa mosque suicide bombing (1 July 2015, 97 dead), Dalori IDP camp attack (30 Jan 2016, 86 dead), Rann airstrike friendly fire (17 Jan 2017, NAF bombs IDP camp, ~115 dead), Dapchi schoolgirls (19 Feb 2018, 110 girls, Yobe but Borno-axis), Metele attack on 157 Bn (18 Nov 2018, ~100+ soldiers killed), Auno attack (9 Feb 2020, 30 travellers burned alive), Zabarmari rice-farmer massacre (28 Nov 2020, 110 farmers beheaded), Geidam Custodial Centre break (12 Apr 2021).Impunity Loop
Death of Shekau (19 May 2021) — Abubakar Shekau detonates a suicide vest in Sambisa Forest during an ISWAP raid on his camp; ISWAP becomes the dominant faction.Northern Abandonment Cycle
Mass JAS surrender (2021–2024) — under Governor Babagana Umara Zulum (2019–), c. 180,000 fighters and families surrender under Operation SAFE CORRIDOR / Borno Model Camp at Hajj Camp, Maiduguri; concurrent attacks continue.Northern Abandonment Cycle
2024 Konduga and Gwoza female suicide bombings (29 June 2024) — coordinated triple suicide attack at a wedding, funeral and hospital, 32 killed; first major bombing in Borno in two years.