Jonathan Gray journeyed to Tbilisi in Georgia, to see the celebrations marking Nina Ananiashvili’s 30 years on stage. Here, he offers a personal tribute to a great ballerina

Not so very long ago, it was not unusual for a ballerina’s career to last well into her forties and beyond – just think of some of the great names from the past, like Anna Pavlova, Galina Ulanova, Margot Fonteyn, Maya Plisetskaya, Antoinette Sibley or Lynn Seymour.