William FitzOsbern, Norman Count of William the Conqueror, established Monmouth Castle between 1066 and 1069 as a counterpart to his other major castle at Chepstow. It was originally an earth and timber ringwork fortress, which was listed in the Domesday Book. The wooden castle had stonework added before 1150.
After briefly being held by Simon de Montfort, 6th Earl of Leicester, Monmouth Castle passed into the hands of Edmund Crouchback, Earl of Lancaster and son of Henry III in 1267. He redeveloped the castle, building the Hall and took it as his main residence in the area. It was further improved in the early 14th century, probably by Crouchback's grandson, Henry of Grosmont, 1st Duke of Lancaster. During this period large decorated windows were installed in the upper part of the Great Tower which also had a new roof. As a town developed around the castle, the castle's defences were augmented by a town wall and fortified bridge, built at the end of the 13th century.
Edward II briefly was held prisoner in the castle before he was transferred to Berkeley Castle where he died. The castle was a favourite residence of Henry Bolingbroke, later King as Henry IV. It was here that in 1387 the future King Henry V of England was born, to Bolingbroke's first wife Mary de Bohun.
Over the centuries, as its defensive function diminished, the outer bailey of the castle became increasingly used as a market place, later (and now) known as Agincourt Square. During the sixteenth century, when Monmouth became the county town of the newly formed shire of Monmouth, the county's Courts of Assize began to be held in the castle's Great Hall.
In the tumult of the English Civil War, Monmouth Castle changed hands three times, finally falling to the Parliamentarians in 1645. Oliver Cromwell visited Monmouth in 1646, and according to tradition ordered the slighting (demolition) of the castle. Great Castle House was built in 1673, on the site of the old round tower, by Henry Somerset, 1st Duke of Beaufort.
Only fragments of the castle, including the Great Tower and Hall and parts of the walls, remain above ground, and on the site Castle House and Great House have been built. In 1875, the Royal Monmouthshire Royal Engineers Militia, the senior Territorial Army regiment today, made it their Headquarters building and so it remains. It is one of the few British castles in continuous military occupancy. The Royal Monmouthshire Royal Engineers museum is located in the stable block attached to Great Castle House. It includes exhibits relating to the history of the regiment from 1539 to the present day.
References:Towering 52 meters above the sea, Bengtskär lighthouse is the tallest one in Scandinavia. The building started in in 1905 after the shipwreck of S/S Helsingfors and was completed in 1906. The lighthouse was designed by architect Florentin Granholm. On December a special petrol lantern, designed and built in Paris, was brought to Bengtskär and installed atop the tower.
German fleet bombarded Bengstkär in the First World War in 1914. Since the Gulf of Finland was heavily mined, it was not until 1919 that the surrounding seas were declared safe for shipping, that the light was lit again.
After the war the military value of Bengtskär increased as part of the defence system of independent Finland. In Second World War (1941) Soviet Union made a suprise attack to island. After a bloody battle, the small Finnish garrison emerged victorious. Intermittent repairs to the facility continued during the post-war period.