Based on the clue 'a group of 3 men collectively responsible for the ...', what is the answer?

Based on the clue 'a group of 16th century german princes started thi...', what is the answer? Based on the clue 'a group of 19th c authors is called the knickerboc...', what is the answer? Based on the clue 'a group of 2 ballplayers pitcher catcher is calle...', what is the answer? Based on the clue 'a group of 3 in power or a vehicle drawn by 3 hors...', what is the answer? Based on the clue 'a group of 3 musically', what is the answer? Based on the clue 'a group of 3 under the zodiac sign of the lion', what is the answer? Based on the clue 'a group of 3 with or without a holy ghost', what is the answer? Based on the clue 'a group of 3rd graders got a bill passed to make t...', what is the answer?