The Princeton Reunions are an annual college reunion event held every year on the weekend before commencement at Princeton University. It is known as the best-attended college reunion in the world. Known simply as "Reunions", this event brings back to campus upwards of 25,000 alumni and guests for a four-day celebration featuring large outdoor tents, elaborate costumes, sporting events, alumni and faculty presentations, fireworks, and bands from rock to swing.
A Princeton Companion places the advent of Princeton reunions shortly after the end of the Civil War. The 1890s (especially the University's 150th anniversary in 1896) saw increasing interest, although it was not until the 1950s that Reunions took on today's level of organization, particularly with respect to on-campus housing for returning alums.
The Alumni Parade, known today as the P-rade, is the capstone of the Reunions weekend. Held on Saturday, it is the last major event — save for the fireworks display (introduced in 1996 in celebration of the 250th year since the University's founding.) The 25th Reunion class heads the parade; they are led by the Princeton University Band, which plays traditional songs such as Going Back to Nassau Hall.
The P-rade then proceeds with members of each class from oldest to youngest, accompanied by spouses, children, family members, and even pets. Alumni of the Graduate School normally take the place of the 25th reunion in the sequence. In 2000 and 2001, to celebrate the centennial of the Graduate College, the Graduate School alumni marched immediately behind the 25th Reunion class. Each year, the University president honors the oldest returning alumnus by presenting him with a silver cane donated by the class of 1923. The bearer of that cane from 2002 to 2005 was Leonard Ernst '25, and from 2006 to 2012, the bearer had been fellow '25 graduate Malcolm Warnock, who was 107 at his final Reunion appearance in 2012. Ernst, Warnock, and most older alumni are typically chauffeured along the parade route by golf carts, but in 2001, the then-96-year-old Warnock impressed everyone by walking the last segment of the P-rade, waving his cane toward an appreciative crowd.
Classes celebrating a major reunion (multiples of five—5th, 10th, and so on) often wear themed costumes, which have ranged from Dutch boys and Roman legionnaires to firefighters and Uncle Sam lookalikes. Costumes and themes are often completely unrelated to Princeton or the year the class graduated.
Frequently, classes will hire musical groups, such as the Mummers, local high school marching bands, and a calliope, to lead them through the parade.