was a feudal domain under the Tokugawa shogunate of Edo period Japan, located in Tà Âtà Âmi Province. It was centered at Yokosuka Castle in what is now the Matsuo district of the city of Kakegawa in Shizuoka Prefecture.
In February 1601, à Âsuga Tadamasa, lord of Kururi Domain in Kazusa Province, was allowed by Tokugawa Ieyasu to return to his ancestral estates in Tà Âtà Âmi, and was granted the status of a 55,000 koku daimyà Â. à Âsuga Tadamasa was the son of the Castellan of Yokosuka Castle and had been relocated by Toyotomi Hideyoshi along with Ieyasu to the Kantà  region. During the unsettled period following HideyoshiâÂÂs death, à Âsuga Tadamasa developed a reputation for his upright leadership, and was a strong supporter of Ieyasu. However, his son succeeded to Tatebayashi Domain (110,000 koku) in Kà Âzuke Province, and Yokosuka Domain reverted to tenryà  status in December 1615.
In October 1619, Matsudaira Shigekatsu was transferred from Sekiyado Domain in Shimà Âsa Province and assigned revenues of 26,000 koku at Yokosuka. His son, Matsudaira Shigetada, former castellan of Sumpu Castle became daimyà  in 1621, and had his revenues increased to 40,000 koku before being transferred to Kaminoyama Domain in Dewa Province the following year.
Yokosuka Domain was assigned next to rà Âjà « Inoue Masanari, with revenues now set at 52,500 koku. His son, Inoue Masatoshi inherited only 47,500 koku in 1628, with the remaining 5,000 koku assigned to his younger brother. However, he was rewarded with 2,500 koku by Shà Âgun Tokugawa Iemitsu for his role in the Tokugawa Tadanaga affair, and was thus ranked as 50,000 koku daimyà  when he was transferred to Kasama Domain in Hitachi Province in 1645.
The next inhabitant of Yokosuka Castle was Honda Toshinaga, formerly daimyà  of Okazaki Domain in Owari Province. Honda proved to be a very unpopular ruler, spending prolifically on prostitutes and sake, ignoring matters of governance, imprisoning or executing his advisors and establishing a network of spies and informers throughout the domain. After severely increasing taxes and issuing a series of 100 repressive ordinances in 1682, the domain was struck by a typhoon, after which the population rose in revolt. Honda was arrested by officials from the Tokugawa Shogunate and imprisoned within Edo Castle, where he was charged with 23 charges of official misconduct. However, he was later pardoned, and assigned to Murayama Domain in Dewa Province (10,000 koku).
Following this incident, Yokosuka Domain was assigned to Nishio Tadanari, formerly of Komoro Domain, Shinano Province, whose family ruled for the next eight generations until the Meiji Restoration.
The domain had a population of 2,644 people per the Kyà Âhà  period (1716-1735) census, which decreased to 2525 people per the Keià  period (1865-1867) census. The domain maintained its primary residence (kamiyashiki) in Edo at Soto-Sakura, in what is now Kasumigaseki, Tokyo.
During the Bakumatsu period, the eighth (and final) daimyà Â, Nishio Tadaatsu, initially attempted to remain neutral, but later contributed his forces to the imperial armies. In February 1869, he was transferred by the new Meiji government to the short-lived Hanabusa Domain in Awa Province and Yokosuka Domain was absorbed into the new Shizuoka Domain created for retired ex-Shà Âgun Tokugawa Yoshinobu. .
As with most domains in the han system, Yokosuka Domain consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields.