1902 – Old Grammarians established
1912 – Old Grammarians defeat Clapham Rovers (FA Cup Winners in 1880)
1919 – Old Grammarians elected to Old Boys League
1920 – Old Sinjuns established & elected to Surrey Junior League
1923 – Old Sinjuns elected to Old Boys’ League
1937 – Old Grammarians winners Old Boys League & elected to Southern Olympian League
1971 – Old Sinjuns winners AFA (Surrey) Senior Cup
1976 – Old Grammarians winners Old Boys Cup (Arthur Dunn)
1979 – Old Grammarians defeat Old Sinjuns in the London Old Boys Cup final
1980 – Old Grammarians winners London Old Boys Cup & AFA Senior Cup
1982 – Old Grammarians winners Southern Olympian League & AFA Senior Cup
1987 – Old Grammarians winners Southern Olympian League & League Cup
2002 – Old Sinjuns & Old Grammarians elected to the Amateur Football Alliance after reorganisation of leagues
2005 – Old Grammarians winners AFA Veterans Cup
2005 – Old Sinjuns merge with Old Grammarians to form Sinjuns Grammarians

*note only first team major successes highlighted