Most of the castle today dates from the time of Sir Lawrence. He built a 'dwelling house' over and around the gate house of the original fortress which forms the centre of the present castle, and either built or restored two flanking towers n either side. A generation later these towers were incorporated into the house also, as shown in a drawing of 1668.

1640-1700
Sieges And Survival
In 1642 the Molloys, Coghlands and Ormonders set fire to the town, 'blew upon their bagpipes and beat upon their drums and fell dauncinge in the hills'. The castle was besieged and finally capitulated when one of the masons who had been involved in the construction of the flanker placed a mine underneath it.

Trouble came again in 1690 when Birr, garrisoned by the Williamites, was besieged by the army of the Duke of Berwick. Cannon balls flew through the parlour window, leaving marks in the walls of the north flanker which are there to this day. lady Parsons gave up the lead cistern she used for salting beef to be melted down for bullets, and the besieging army was finally repulsed.

The sieges left their mark on the park as well as on the castle, and the lines from which the castle was besieged can still be seen leading to Cromwell's Hollow.

In spite of these disturbances the beginnings of the Formal Gardens were laid out at this time and the famous Box Hedges were planted. The wives and daughters of the house grew vegetables, collected medicinal remedies - those for the curing of 'green wounds' and 'bruises inward and outward caused by 'fall or blow' presumably proving useful in times of trouble. In a firm hand and with uninhibited spelling they wrote cookery recipes for preserving their fruits and vegetables for ' chicking fricasee' and hartichoake pie'!

1700-1800
Peace and Politics
Peace came again with the eighteenth century. Sir William Parsons, the 2nd baronet, was a friend of Handel, who gave him an engraved walking stick in consideration of the patronage which led to the Messiah being first performed in Dublin.

His grandson, another Sir William, the 4th baronet, began to landscape the park. He turned bog into lake, planted beech trees and tore down the last of the old towers of the original fortress so as to complete the sweeping view of his beautiful park.

He also devoted much of his time to the Volunteer movement which sprang up towards the end of the eighteenth century, ostensibly to defend Ireland from the threat of French invasion, but effectively to force the English government to give concessions to the Irish Parliament.

His son, Sir Lawrence, 5th baronet, became well-known as a patriot statesman, whose friend and colleague, Wolfe Tone, referred to him as 'one of the very very few honest men in the Irish House of Commons'. This honesty led him not only to oppose the Union with all his strength, but also to expose the bribery the British used to push it through.

1800-1840
Architecture and Earldom
Sir Lawrence retired from politics at the beginning of the 19th century, disgusted at the Act of Union, though he later accepted the post of Joint Postmaster General and saw Dublin's magnificent GPO build during his term of office.

He devoted the rest of his life to literature (being a great friend of Maria Edgeworth and to building. The castle began to take its final from at this time with Sir Lawrence turning the old house back to from in order to face the park, heightening and crenelating it in the new Gothic style and adding the great Gothic saloon whose windows can be seen looking down on the waterfalls of the Camcor. In 1807 Sir Lawrence inherited from his uncle in County Longford the title of Earl of Rosse and had by this time married Alice Lloyd of Gloster. He disapproved of sending his children away to school and they were brought up by tutors at home in an enlightened atmosphere of building and construction and even engineering. For instance it was during his time that the Suspension Bridge was built over the Camcor. This is the earliest known anywhere and is first described in 1826 as a 'curious wire bridge which hangs as it were suspended in the air just under the castle'.

1840-1900
Astronomy and Engineering
The 2nd Earl's eldest son William who became the 3rd Earl of Rosse, constructed in the 1840's, the giant telescope which is located in the middle of the Park. He designed and built it himself with no more than the means then available in central Ireland. The huge 6' speculum was cast in a furnace which was constructed at the bottom of the moat and was fired by turf off the local bogs. The immense power of the telescope enabled the Earl to see far further into space than anyone had done before, and attracted astronomers from as far afield as the U.S., Australia and Imperial Russia, whence they made the pilgrimage to Birr as the only observatory in the world which could see so far into space.

The third Earl became especially interested in the nebulae and particularly in those of a spiral nature. He recorded them in drawings whose clarity was not matched until the powerful photography of the next century, and reproductions of some of these may be seen on display, together with some of the original eyepieces and artefacts, in the viewing pavilion alongside the Telescope.

Like his father, he educated his sons at home, and the eldest, Lawrence, who succeeded as 4th Earl in 1867, also became a famous astronomer, though he concentrated mainly on the moon, whose heat he succeeded in measuring with a special instrument of his own invention. His youngest son, Charles Algernon Parsons, was an even greater inventive genius and developed the Steam Turbine, which is commemorated by the issuance of an Irish postage stamp.

1900-1980
Botanising and Beautifying
This period has been devoted mainly to developing the garden with the introduction of increasingly rare plants, trees and shrubs from all over the world. When the 5th Earl inherited in 1908, he flattened the earthworks beyond the moat along the river, making the Terraces where herbaceous borders no give colour below the walls of the moat.

After his early death in the First World War, his son succeeded as 6th Earl and became a plantsman of great renown. His marriage to Anne, daughter of the Messels of Nymans, a famous garden of the National Trust in the South of England, greatly strengthened this latest development. The 6th Earl sponsored and subscribed to plant collected expeditions to the Americas and Eastern Asia and arranged for the first major expedition to be undertaken by a Chinese, when he was on his honey moon in Peking in 1935. The seeds from all these expeditions flowed back to be sown at Birr which now has, as a result, one of the world's greatest collections of trees and shrubs, and one that is particularly strong in species of Chinese and Himalayan origin.

At Birr today shrubs and trees are growing from seed that was collected as far away as Chile, Mexico or Guatemala, the Caucasus or the Himalayas. Lord Rosse himself even collected some from the Temple of Confucius in Peking. Some of these trees are still so rare that seeds have in turn been taken from them for the Royal Botanic Gardens in Kew, where the species were not yet represented.

The catalogue of this collection has recently been up-dated and is available at the gate, together with an educational guide to the fifty trees of greatest distinction, known as the 'Red Tree Trail'. Special mention may also briefly be made of plants in the gardens actually named after the 6th Earl and Countess of Rosse. These comprise a pair of magnolias, which are the real pride of the gardens when they are out in the spring, and the famous peony, Anne Rosse, which won an Award of Merit and the Cory C. This last was a pollinated cross between a peony discovered on one of the Chinese expeditions in 1937, and another, discovered the year before in the Tsangpo Gorge in S.E. Tibet.

Thus international significance is still maintained botanically, as it was established astronomically a century before.