What is the name of the intense phase of developments that began in great britain during the 1700s?

What is an example of a secondary source?

Trench warfare began after germany failed in its initial plan to seize france and bring a quick end to the war. negotiate a temporary truce with the allied forces. attack the allies by sea with its powerful navy. storm across the eastern front to attack russia.

According to this passage, what can be expected of people appointed as judges temporarily?