Constantinople

How did the separation over the calendar change in the Eastern Orthodox Church begin? What exactly happened in Constantinople in 1923? Who were the protagonists and what was their objective?

Since the Œcumenical Patriarchate of Constantinople decided on the issue of the calendar, is it not binding on all Orthodox Christians? Was it lawful to resist the changes introduced by the Holy Synod of Constantinople?

Do the Greek Old Calendarists possess Holy Chrism? How is this possible, since they do not receive it from the Œcumenical Patriarchate of Constantinople?