In the time before deep sea cables carrying telephone lines and the like, the only way that Australia and the British authorities could stay in contact was by carrying messages - either in written form, or in oral form - on ships. As you can imagine, in the era before modern shipping, it simply took several months - the better part of a year - to travel between Australia and Britain (though the length of the journey would decrease across the 19th century, with the advent of clippers and steamships). To give an example, let's take one case of civil unrest, the 1808 Rum Rebellion - it basically took almost two years between the rebellion itself and the arrival in Sydney of a force designed to deal with the rebellion.

On the 26th of January, 1808, there was a rebellion against the governor of New South Wales, William Bligh, by the 'Rum Corps', a group of army officers. Historians disagree about the exact nature of the reasons for the 'Rum Rebellion'; but Bligh said in 1812 that "the thirst after spirits was so very strong that [the settlers] sacrificed every thing to the purchase of them, and the prices were raised by that monopoly to so high a degree that it was the ruin of many of those poor people." The monopoly on rum was controlled by the Rum Corps (thus the name); they were not favourably disposed to Bligh's attempts to dislodge their control of the supply of grog (and other food stuffs). Bligh was also not necessarily the easiest person to get along with, what with having his crew mutiny on him in the Pacific in 1789, back when he was the commander of the HMS Bounty.

In January 1808, a prominent member of the colony, John Macarthur, was put in jail without bail by Bligh on a relatively innocuous charge related to boat maintenance (largely because Macarthur had long butted heads with him, and had recently been making incendiary speeches against him). The Rum Corps used this as a pretext to A group of three hundred soldiers marched to Government House, invaded the house and found and arrested Bligh, announcing that they had deposed him, with Major George Johnston announcing himself as the new governor. Bligh stayed under house arrest for twelve months, plotting his revenge.

Obviously, a group of army officers deposing the British-government-appointed governor was not going to be seen positively by the British government - it was treason. However, news of the rebellion only reached England in September 1808 - and yes, the only way news of the rebellion was going to reach England was via ship, whether by oral communication or letters.

It took from September 1808 to May 1909 for the British government to organise for the 73rd regiment, headed by Lachlan Macquarie, to be sent to the colony (the British military were a little distracted by one Napoleon Bonaparte at this point). Macquarie, who was to be the new governor of the colony, had orders to arrest the Rum Rebellion's leaders and send them back to Sydney, and he travelled on the HMS Dromedary, a 40-gun frigate of the era. However, by this point, unbeknownst to Macquarie, the Rum Rebellion's leaders were already en route to England.

Joseph Foveaux, had been Lieutenant-Governor of Norfolk Island until 1804, when he headed back to England; in 1807 he had been ordered to return back to Norfolk Island if sufficient inhabitants remained there. They did not, and in that event, his orders were then to return to Sydney. So he arrived in Sydney in at the end of July 1808, and discovered that Bligh was under house arrest - and that he was the senior officer to George Johnston, the Rum Corps' governor. Making him the one in charge. Foveaux was not inclined towards reinstating Bligh in the political situation (e.g., the Rum Corps would have made life difficult for him if he had), and Foveaux basically frequently sent letters to William Paterson, Lieutenant Governor in Hobart (Foveaux's senior officer) urging him to take the reins in Sydney. Paterson prevaricated for a variety of reasons - not least of which was that he had challenged one of the main ringleaders of the rebellion, John Macarthur, to a duel in 1801. But finally, he sailed to Sydney in January 1809 and took charge. In March 1809, Paterson arranged to send Bligh and Macarthur to England to plead their cases, though he otherwise was too ill and too weak as a leader to change much about the way the Rum Corps were running the colony. However, despite Paterson's orders, Bligh refused to return to England (considering Paterson's rule illegitimate), and instead sailed for Hobart, hoping for the allegiance of the Tasmanian Lieutenant-Governor (who humoured Bligh but refused to back him).

While en route to Sydney, in Rio de Janeiro, Macquarie discovered that George Johnston and Macarthur had just passed through the town on the way to England, with Johnston to be court-martialled (Macarthur at this point was a free citizen, and would not face court-martialling). Arriving in Sydney, Macquarie and his regiment found the colony "in a perfect state of tranquility"; days later, he was sworn in as governor on January 1st, 1810. With his regiment's military force prominently displayed as he entered Sydney, he promptly annulled all the acts of the government since the deposing of Bligh, and sent Bligh to England so he could give evidence in the court-martial of Johnston.

Sources:

• The Fatal Shore, Robert Hughes, 1986

• The Colony, Grace Karskens, 2009

• The Australian Dictionary of Biography*, 1967

• Mutiny And The Trial of Lt. Col. Johnston, specifically the extracts from the 1901 Historical Records Of New South Wales, Vol. 7 by F.M. Bladen.

• Proclamation, Sydney, New South Wales, February 4, 1809, William Paterson