Sounding the “Last Post” – The Last Post is one of a number of bugle calls in militaryBugler
It is believed originally to have been part of a more elaborate routine, known in the British Army as “Tattoo”, which had its origins in the 17th century.

During the evening, a duty officer had to do the rounds of his unit’s position, checking that the sentry posts were manned and rounding up the off-duty soldiers and packing them off to their beds or billets.  He would be accompanied by one or more musicians.
The “First Post” was sounded when the duty officer started his rounds and, as the party proceeded from post to post, a drum was played.  The drum beats told off-duty soldiers it was time to rest – if the soldiers were billeted in a town, the beats told them it was time to quit the pubs.  “Tattoo” is a derivation of doe den tap toe, Dutch for “Turn Off The Taps”, a call which is said to have followed the drum beats in many a Dutch pub while English armies were campaigning through Holland and Flanders in the 1690s. (It is also from this routine that American practice of “Taps” or “Drum Taps” originated Another bugle call was sounded when the party completed their rounds, when they reached the “Last Post”; this signalled the night sentries were alert at their posts and gave one last warning to any soldiers still at large that it was time to retire for the evening.  The “Last Post” was incorporated into funeral and memorial services as a final farewell and symbolises that the duty of the dead is over and that they can rest in peace.
The “Rouse” And The “Reveille” – After a period of silence, flags are raised from half-mast to the masthead as “The rouse” is sounded.
Today it is associated with the “Last Post” at all military funerals, and at services of dedication and remembrance.  Since Roman times, bugles or horns had been used as signals to command soldiers on the battlefield and regulate soldiers’ days in barracks.  “Reveille” was a bright cheerful call to rouse soldiers from their slumber, ready for duty; the call has also been adopted to conclude funeral services and remembrance services.

The Rouse” symbolises an awakening in a better world for the dead and rouses the living, their respects paid to the memory of their comrades, back to duty.”The Rouse” is a shorter bugle call, which, as its name suggests, was also used to call soldiers to their duties.  It is “Rouse”, due to its much shorter length, which is most commonly used in conjunction with the “Last Post” at remembrance services.  The exception is the Dawn Service, when “Reveille”is always played.