Montserrat was, after France had taken possession of the island a few times, a British
colony since 1784, so that since that year the flag of the United Kingdom flew
over the island. On land, and until 1864 also at sea, individuals, citizens and
also the authorities represented their status as citizens or bodies of the
United Kingdom by using the Union Jack, known as the "Union Flag". This means
that on land, the Union Flag is the national and state flag. On land, the "Blue
Ensign" (actually the state flag at sea) with the country's badge/coat of arms
may also be used as the national flag for decorative purposes if the governor
has authorised this, for a limited period of time, e.g. at an event (including
outside the country) or for differentiation purposes if the use of the Union
Flag would be inappropriate or likely to cause confusion. On land, however, the aspect ratio of the flag should be 3:5. A "Blue Ensign" is a
dark blue baunting with a representation of a flag – the British Union Jack – in
the upper corner and the country's badge in the flying end of the flag. The
Union Jack emphasises the links with United Kingdom.
United Kingdom introduced a flag system in 1864 in which:
• war ships fly the "White Ensign" (naval flag), a white flag often with an uninterrupted red St. George's-Cross and with the Union Jack in the upper staff quadrant of the flag,
• merchant ships fly a "Red Ensign" (also named "Civil Ensign" → civil flag, the real merchant flag), a red flag with the Union Jack in the upper staff quadrant of the flag, and
• governmental ships fly the "Blue Ensign" (flag for the use by the gouvernment → the actual state flag), a blue flag with the Union Jack in the upper staff quadrant of the flag.
From 1865, the ships of the colonial governments were allowed to use a Blue Ensign with a badge at the flying end. The respective governments were to provide appropriate badges. Merchant ships and seafaring privateers from colonies were only allowed to use a Red Ensign with a badge if the British Admiralty had issued a corresponding licence for that colony. Such a badge was often a regional landscape depiction on a disc, often showed ships, historical events or could simply be a kind of logo. Very often a badge also contained the name of the country or a motto. However, some possessions had a coat of arms from the beginning or were given their own coat of arms over the years and the badge was abolished. To ensure a largely uniform appearance in the flying end of the flags, coats of arms and other symbols were displayed on a white disc in the size of the former badges. However, there were also exceptions, as some colonies dispensed with this white disc and placed their coat of arms or even just the shield – sometimes enlarged – directly on the bunting. As early as the 1940s, the white disc was removed and the coat of arms was applied directly or enlarged. This conversion process took place gradually, nowhere simultaneously and completely. In some British possessions flags with the white disc are still in use today, in others no longer and in some areas both variants exist side by side.
The badge of Montserrat shows a female figure with a harp in her hand, holding on to a cross. Until 1960, it was depicted on the flag within a white disc and was further enlarged in 1999.
From 1832 to 1958, the area was part of the British colony of the Leeward Islands, a federal colony consisting of individual sub-areas, sub-colonies or islands. These individual colonies had their own flags, also called "Blue Ensigns" with their own badge, for use by the governments of these colonies. The overarching political entity of the British Leeward Islands also had its own Blue Ensign with its own Leeward Islands badge. This badge was created in 1871 and showed a pineapple on a coastline with two ships. The governor also used it on his flag. He was represented locally, in the associated sub-territory, sub-colony or island, by an administrator. The federal colony ceased to exist when it was incorporated into the Federation of the West Indies, led by a Governor-General. Locally, in the associated sub-territory, sub-colony or island, the highest representative of the Crown retained his rank. He remained an administrator or even governor. The local flags (e.g. blue or red ensigns, i.e. separate state or merchant flags) have been retained.
From 1958 to 1962 the territory was also part of the British colony "Federation of the West Indies". This political project was an attempt to unify the administration and to create a state modelled on Canada, but also to counteract the independence efforts of the associated islands and colonies. However, jealousies arose between the large and small islands and even led to open dispute. The flag of the "Federation of the West Indies" was a light blue flag with four horizontal white wavy lines and a golden disc in the middle. It symbolized the sun over the Caribbean Sea. There is some doubt about the color of the blue; it is often assumed to be the usual British heraldry blue. However, a contemporary description calls it an "imperial blue" which would be light blue and many contemporary prints also show this light blue.
The coat of arms of Montserrat – used as badge on the flag – shows a feminine figure with a harp in the hand which holds on to a cross. It was introduced in 1909.