তিনশতবার্ষিকী, তিনশত বর্ষপূর্তি উত্সব
তিনশতের
(1) The 300th anniversary (or the celebration of it
(2) The 300th anniversary (or the celebration of it)
(1) Gilbert was more celebrated in his tercentenary year than he will be today.
(2) In 1916 he was knighted on the stage of Drury Lane at the conclusion of a special, tercentenary performance of Julius Caesar.
(3) The focal point of the tercentenary celebrations will take place in Germany - the battalion's current base - next Saturday, when it will receive new colours from the present Duke of Wellington.
triennial
tercentennial