In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
Which event acted as the first domino to change the Fujiwara's path in history?, Context: As the Soga clan had taken control of the throne in the sixth century, the Fujiwara by the ninth century had intermarried with the imperial family, and one of their members was the first head of the Emperor's Private Office. Another Fujiwara became regent, Sesshō for his grandson, then a minor emperor, and yet another was appointed Kampaku. Toward the end of the ninth century, several emperors tried, but failed, to check the Fujiwara. For a time, however, during the reign of Emperor Daigo (897-930), the Fujiwara regency was suspended as he ruled directly.
Answer:
by the ninth century had intermarried with the imperial family