Celtic cavalry fought against Caesar’s invasion of the British Isles in 55 B.C., and cavalry helped carry the day for William the Conqueror at Hastings in 1066. But those are recent events in light of the earliest artifact to be shown at All the Queen’s Horses: The Role of the Horse in British History at the Kentucky Horse Park’s International Museum of the Horse, in Lexington, April 26 through August 24. On display will be the oldest example of human art ever found in Britain: a piece of bone incised with a beautifully drawn profile of a horse’s head—from 10,000 B.C.

According to a press release, visitors to Entertaining America: Jews, Movies, and Broadcasting , an exhibit on display at the Jewish Museum, in New York City ( www.thejewishmuseum.org ), through September 14, will see “a series of ‘star shrines’” that “evoke a sense of the public’s fascination with the Jewishness of such icons as Fanny Brice, Betty Boop, the Marx Brothers, John Garfield, Marilyn Monroe, and Barbra Streisand.” Elsewhere “specially built environments invite visitors into experiences that include watching silent movies in a Lower East Side storefront; rediscovering the ’alternative media’ of American Yiddish film and radio; dropping into a 1950s living room where The Goldbergs are on TV; and lounging with a laptop computer in a Seinfeld -like coffee shop.” Should lines at the last of these environments prove too long, visitors can simply walk a block east to Madison Avenue and experience it in real life.

The Isabella Stewart Gardner Museum ( www.gardnermuseum.org ) opened in Boston in 1903. In the century since, the only change to the core collection occurred in 1990, when 13 paintings were stolen, for Gardner, a wealthy socialite, specified that the artworks she gave the museum must be displayed exactly as she left them. Despite this stricture, the museum has been far from static, as curators have added music to its offerings and exhibited a variety of artists old and new in other parts of the building. To mark its centennial, the museum is mounting two exhibits about Gardner, one focusing on her role as a pillar of Boston’s art world (with watercolors by Gardner herself) and one on her Venetian circle of artistic friends. These open in April; other exhibitions, concerts, and lectures celebrating the centennial will continue through the year.