A sudden flare-up in Syria’s long-running civil war last week saw rebel forces retake the country’s second-largest city, Aleppo, in a massive blow against President Bashar al-Assad’s government.

The Syrian civil war has reignited after four years of docility, with five main players deciding the course of events.

Syrian opposition forces in recent days seized Aleppo, one of Syria's largest cities, reigniting a 13-year civil war.

Syrian rebels shocked the country with a lightning offensive on its biggest city and the surrounding region starting last week, upending a 13-year-old civil war that had been dormant for several years.

A lightning offensive in Syria last week broke a prolonged stalemate 13 years into Syria's civil war and emphasized the vulnerability of Syrian President Bashar al-Assad's regime. Why it matters: Rebels last week reclaimed nearly all of Aleppo,

The 13-year civil war in Syria has roared back into prominence with a surprise rebel offensive on one of Syria’s largest cities and ancient business hub.

Syrian militants advance on the city of Hama after taking Aleppo. Fabrice Balanche of the University of Lyon says the Iranian-backed forces of the Syrian government are not strong enough to face down the coalition of militants backed by Turkey.