Who, what, and why? Hotel heiress Nicky Hilton married James Rothschild in a lavish London wedding this past weekend, but there were numerous family absences, including her brother Conrad Hilton, aunt Kim Richards, and uncle Mauricio Umansky.

Hilton, 31, tied the knot with her financier beau at the Orangery in Kensington Gardens at Kensington Palace, where the two were celebrated by her sister Paris, aunt Kyle Richards, and her hotel mogul father Rick and mom Kathy.

The bride’s younger brother Conrad missed out on the occasion due to his legal troubles. The hotel heir, who was arrested after leading a high-speed police chase last August, was scheduled to appear for a court arraignment on Monday, which he missed. According to local paper The Desert Sun, the troubled scion’s failure to appear in court resulted in the preparation of an arrest warrant. If he misses his Sept. 17 court date, the warrant will be executed.

Meanwhile, Nicky’s embattled reality star aunt Kim also missed the nuptials this weekend due to her own stint in rehab. Kim was arrested this past April after causing a booze-fueled scene at the Beverly Hilton. She subsequently checked into rehab, and it was confirmed to Us by multiple sources that she will not be returning to the Real Housewives of Beverly Hills.

While Kim’s sister Kyle was present at the star-studded celebration, the brunette beauty’s husband, Mauricio, was another noticeably missing relative. A source tells Us Weekly the reason for his absence was that he and the father of the bride, Rick, have not been speaking after a business fallout.