Context: In the early days of association football, known simply as football or soccer, friendly matches (or "friendlies") were the most common type of match. However, since the development of The Football League in England in 1888, league tournaments became established, in addition to lengthy derby and cup tournaments. By the year 2000, national leagues were established in almost every country throughout the world, as well as local or regional leagues for lower level teams, thus the significance of friendlies has seriously declined since the 19th century.

Question: What were the most common type of matches in the early days of soccer?
Answer: friendly matches (or "friendlies")

Question: When did the Football League begin in England?
Answer: 1888

Question: By what year had national football leagues been formed in nearly every country?
Answer: 2000

Question: What did the growth of national leagues cause a serious decline in?
Answer: the significance of friendlies

Question: During the early days of what sport were unfriendly matches the most common matches?
Answer: Unanswerable

Question: When did the football league beginning your?
Answer: Unanswerable

Question: What was established in addition to brief derby in cup tournaments?
Answer: Unanswerable

Question: By what year were regional leagues establish in almost every country?
Answer: Unanswerable

Question: What increase the significance of Friendly's since the nineteenth century?
Answer: Unanswerable