Iran's dramatic aerial attack on Israel follows years of enmity between the countries and marks the first time Iran has launched a direct military assault on Israel. The hostility between the countries has only worsened in the six months since Hamas launched its attack on Israel, which set off a war that continues to threaten to drag the entire region toward a broader conflict.

Here is a look at the key events leading up to Iran's assault:

Hamas attacks Israel

Oct. 7

Thousands of Hamas-led militants storm across the border into Israel, killing 1,200 people, mostly civilians, and taking roughly 250 captive, according to Israeli authorities. The assault triggers a devastating war that has killed more than 33,700 people, mostly women and children, according to local health officials. In launching the assault, Hamas hopes other regional enemies of Israel's will join. U.S. President Joe Biden warns Israel's regional foes not to get involved and sends military support to the Middle East.

Hezbollah joins the war, at a low level

Oct. 8

A day after Hamas' attack, the Iran-backed Lebanese Shiite Hezbollah begins firing toward Israel, setting off months of low intensity but deadly cross-border fighting that displaced tens of thousands of people on both sides of the border.

Houthis stage attacks

November

The Yemeni rebels, who are supported by Iran, launch a campaign of drone and missile attacks on shipping assets in the Red Sea beginning in November, describing their efforts as a way to pressure Israel to end the war against Hamas. They also fire missiles toward Israel, although those largely fall short or are intercepted.

Israel widely blamed for Damascus strike

Apr. 1

Two Iranian generals with the country's paramilitary Revolutionary Guards are killed in the Syrian capital in a strike on an Iranian consular building that is widely blamed on Israel, although it does not publicly acknowledge it. Iran promises revenge.

Iran launches major aerial assault on Israel

April 14

Israel says more than 300 drones, cruise and ballistic missiles are launched by Iran, an extraordinary assault that is thwarted almost entirely by Israel's aerial defense array and a coalition of countries repelling the onslaught. While no major damage is caused, the world braces for Israel's response.