Short answers, pulled from the story.
The name Salafiyyah emerged as a self-designation in the late 19th century. Historians trace this movement's intellectual roots to the mid-1800s opposition against European imperialism led by figures such as Jamal al-Din al-Afghani and Muhammad Abduh.
Contemporary Salafism emerged from the 1960s as an intellectual hybrid where Albanian scholar Muhammad Nasir al-Din al-Albani was most responsible for this transformation. He is respected by all contemporary Salafis as the greatest hadith scholar of his generation.
Salafis define their reform project primarily through creedal tenets known as Tawhid which categorizes the oneness of God into three types: Lordship, Worship, and Names and Attributes. They place great emphasis on practicing actions according to the known sunnah while rejecting religious innovation known as bid'ah.
As of 2017 journalist Graeme Wood estimated that Salafis make up fewer than 10% of Muslims globally. Despite their minority status Salafi teachings have become mainstreamized within modern Muslim communities.
Since the 1960s Saudis have funneled over USD 100 billion into funding schools and mosques worldwide. Estimates suggest spending on 1,500 mosques 210 Islamic centers and dozens of academies costs around $2.3bn annually since 1975.