How did the terror organization Hamas acquire immense power and, with its influence in the region, be able to launch the most brutal attack on Israel on 7 October?

For over a decade, Israel has clashed with Hamas in Gaza, with cycles of violence that California-based think tank Rand Corp. said were defined by periods of intense fighting followed by relative lulls.

Following the Six-Day War in 1967, when Israel captured Gaza and placed it under military administration, the conflict with Palestinians who developed settlements there had raged.

Over time, that struggle led to the First Intifada, a Palestinian uprising that lasted from 1987 to 1993, and the emergence of Hamas, the militant Islamist group that now governs Gaza.

Hamas became powerful as leftist secular groups, such as Fatah and the Palestinian Liberation Organization, lost influence.

The 1993 Oslo Accords ended the First Intifada, creating the Palestinian Authority as the governing body of the Palestinian people and stipulating that the PLO would recognize Israel's right to exist.

Ultimately, frustration over delays in implementing the Oslo Accords and tensions over Israel's continued grip on the Palestinians boiled over, sparking the Second Intifada in 2000, a period of intensified Israeli-Palestinian violence.

This led Israel to fortify its border with Gaza and, in 2005, to withdraw from the territory completely after nearly 40 years of occupation.

In a struggle between Hamas and Fatah, Hamas took over Gaza in 2007, as it morphed into a hybrid entity that is part terrorist organization and part pseudo-state.

Hostilities between Hamas and Israel led to the First Gaza War and Operation Cast Lead in December 2008, which ended quickly with Israel's victory and withdrawal in late January 2009.

Between 11 and 13 November 2012, more than 200 rockets and mortar rounds were fired into Israel from Gaza, wounding dozens of civilians and damaging property.