The  Lachish letters, discovered in 1937, contain correspondence between the commanders of Azekah and Lachish 
during the last days before the Babylonian captivity. Some refer to a prophet,which is most likely Jeremiah,
whose name appears in at least one of the letters.Babylonia,along with the Medes,had defeated the Assyrians
and reduced the city of Nineveh to ruins,as foretold by the Prophet Nahum.All lands belonging to Assyria,
including Syria,Judah and Israel became part of the Babylonian empire.At the time,Judah and Syria were the
part of Assyria under control of Egypt.In 609 BC,Necho of Egypt threw off his allegiance to Assyria,
and marched to Charchamesh.The king of Judah,Josiah,still faithful to Assyria,marched to Meggido 
in an effort to stop Necho.II Kings 23:29 and II Chronicles 35:20-24,tell us that Josiah was killed in the battle.
Necho put an end to Assyria,and on his return trip to Egypt,punished Judah for Josiah's intervention in Egypt's affairs,
by dethroning Jehoahaz,the son of Josiah,and taking Him prisoner (II Kings 23:30-34;II Chronicles 36:1--4;Jeremiah22:11-12).
During the reign of Jehoiakim,the second son of Josiah,Egypt lost control of Judah.It was during His reign that
Nebuchadnezzer took advantage of the collapsed Assyrian kingdom and began establishing His reign over the western region.
Some countries opposed Him,as some of his inscriptions tell:
"... inhabitants of the Hittite country, in the month Airu, of the third year of
(Nebuchadnezzar king of) Babylon 
opposed his troops. Nebuchadnezzar) summoned his troops, in 13 days to (the Hittite country)
he marched. Of the people inhabiting Ammanu (i.e., Anti-Lebanon) . . . their heads he beat off . . . (upon poles) he hung. . ."
 (R. W. Rogers: "Cuneiform Parallels to the Old Testament" pp. 369, 370)
Nebuchadnezzer defeated the Hitttites and marched to Judah.This event is told in the Babylonian Chronicles and reflected
in the Bible.
"In the seventh month (of Nebuchadnezzar-599 BC.) in the month Chislev (Nov/Dec)
the king of Babylon assembled his army,
and after he had invaded the land of Hatti (Syria/Palestine) he laid siege to the city of Judah.
On the second day of the
month of Adara ( 16th of March) he conquered the city and took the king (Jehoiachin) prisoner.
He installed in his place
a king (Zedekiah) of his own choice, and after he had received rich tribute, he sent (them)
forth to Babylon." 
 Judah rebelled again under the leadership of Zedekiah,which was probably the basis for Hananiah's prophecy
that Judah would be restored in two years.(Jeremiah 28. 3, 11).
Hananiah apparently believed the rebellion would be a success,which he no doubt was privy to.The rebellion took place
two years after His prophecy,but the outcome was not as he predicted.Jeremiah,as it turned out,was correct in his prediction
that Judah would be under the yoke of Babylon for 70 years.Those who preferred only good news,conspired against Jeremiah 
to silence him.

Letter XVI is  only a broken fragment. However, line 5 supplies us with just a portion of the prophet's name, thus:
[. . . . i]ah the prophet.

Letter XVII, another tiny fragment, contains a few letters out of three lines of the letter. Line 3 gives us just the name:
[. . . . Je]remiah [. . . .]

Letter 6 was written at a time prior to the fall of the cities of Lachish and Azekah,when Jeremiah was proclaiming the wisdom of surrendering to the Babylonians.
"To my lord Jaush. May the Lord let (us) see thee in prosperity! Who am I, thy slave, a dog, that thou hast sent me 
the [lett]er of the King and the letters of the offic[ers, (The same word here is translated 'princes' in Jeremiah 38:4,
Dr. J. W. Jack) say]ing: "Read, I pray thee, and (thou wilt) see (that) the words of the [prophet] are not good, 
(liable) to loosen ("weaken" suggested by Dr. J. W. Jack) the hands, [to make] sink the 
hands of the coun[try and]the city." (Dr. J. W. Jack translates: "the hands of the m[en in the] city.")
My lord, wilt thou not write to [them saying]: "Why should ye do thus: . . . ?"
And as Yahweh your God lives, since your servant read the letters, there has been no peace [?] for your servant."

Jeremiah wrote of this conspiracy to kill Him.
JEREMIAH 38:4.
Therefore the princes said unto the king, We beseech thee, let this man be put to death: for thus he weakeneth the hands 
of the men of war that remain in this City, and the hands of all the people in speaking such words unto them: for this man
seeketh not the welfare of this people, but the hurt. 

The last days of Jerusalem were reflected in  34th chapter of Jeremiah, 
“The king of Babylon’s army fought against Jerusalem, and against all the cities of Judah that were left, against Lachish and against Azekah.”
Because of its strategic position in the Valley of Elah, the city of Azekah was often attacked and destroyed. 

Both Assyria and Babylon traveled through the valley of Elah and destroyed Azekah during ancient times. 
The city of Lachish?located southwest of Azekah?also guarded a significant valley.The Jews had arranged for relay 
communication between Lachish and Jerusalem by means of smoke signals at Azekah, fifteen miles from Jerusalem, and Lachish, 
thirty-five miles distant.A watchman would look for the signal fires of Azekah each day and then write a report
for the King of Lachish, saying something like, ?I can still see the fires of Azekah.?As long as Azekah?s fires kept
burning, the king of Lachish knew that the city still stood.
The people of Jerusalem probably realized it was Jeremiah that spoke the truth when the signal fires of Azekah went out.
It was a sure sign that the rebellion against Nebuchadnezzer was not working.

"May the Lord soon let my lord hear good tidings!
I have carried out all the instructions you have sent me, and have recorded on the page all that you ordered me. 
You instructed me also about the rest house, but there is nobody there. And Shemaiah has taken Semachiah and brought him up
to the city (Jerusalem), and I will write and find out where he is. Because if on his rounds (turnings) he had inspected,
he would have known that we are watching for the signal-stations of Lachish, according to all the signals you are giving,
because we cannot see the signals of Azekah." 
 Like most of the others,Letter Three  was written by a certain Hoshaiah, who was stationed at some military outpost.
He was writing to someone named Jaosh, who apparently was the high commanding officer at Lachish.The letter
was in response to charges concerning a classified document. Hoshaiah's defense was that he could not read
and noone had read the document to Him. 
"Thy slave Hoshaiah writes to inform his lord Jaush. May the Lord give thee prosperous tidings!
And now, I have written to the seer, referring to the letter which thou sentest to me yesterday, and have told him 
that my heart is sick since I had thy letter, and that I declare: "My lord, I cannot read a letter. 
The Lord liveth (to punish me) if anyone has tried to read me a letter. I have not read any letter which came to me,
nor seen anything of it."
And I have been told that the Commander of the army, Achbor,the son of Elnathan, has gone down to Egypt, 
and he has sent an order to take Hodaviah, the son of Ahijah and his men from here.And the letter which Nedabiah, 
grandson (or grand-nephew) of the King, has brought from the prophet to Shallum, the son of Jaddua (or Jada) , saying, 
"Beware!" have I sent to thee. 

It is widely believed that the Seer referred to in the letter was Jeremiah,and Hoshaiah had contacted Him to act as a 
character reference in His defense.It is also believed that the classified document had something to do with Jeremiah,and 
that Hoshaiah had written letters to Jaush in defense of the prophet.The theme of the letters,according to some 
interpretations,seem to be the prophecy of Jeremiah and the secrecy of the planned rebellion,which Jeremiah states will
not work.The charges against Hoshaiah may have to do with leaking plans of the rebellion.The fact that Hoshaiah was
charged with revealing a secret is apparant in 
Letter II 
"To my lord Jaush: May the Lord (Yhwh i.e., Jehovah) soon let my lord hear pleasant tidings! Who am I, thy slave,
a dog, that thou hast remembered me? May the Lord investigate (and punish me) if I have spoken a thing, of which I did 
not even know."


In Letter V the writer is again earnestly protesting his innocence. He writes:
"May the Lord soon let my [lord] hear good and pleasant tidings!
Who am I, thy slave, a dog, that thou [hast s]ent me ....iah's le[tters ?] [And now] I have returned the letters to thee.
May the Lord tell thee what has [happened]! Who am I, that I should curse the king's seed in (the name of) the Lord? 

Letter I is a list of names. It may have been a list of witnesses to accompany one of the letters. 

Some of these names were already known from Scripture.
Gemariah son of Hissiliah
Jaazaniah son of Tobshillem
Hagab son of Jaazaniah
Mibtahiah son of Jeremiah
Mattaniah son of Neriah

Letter XVIII gives a few words, which may have been a postscript to Letter VI. It states:
This evening, [when cometh Tob]shillem, (I) shall send thy letter up to the city (i.e., Jerusalem).