[1.1] This should be understood as an introductory clause not (as some translators have done) as part of the following sentence.
[Cinggis Qaghan-u] With the addition of -u the proper noun Cinggis Qaghan is placed in the genitive case, and therefore qualifies the following noun ijaghur.
Translation: Chinggis Khan’s origin(s) or The Origin(s) of Chinggis Khan
Gloss: Herein lies an account of the origins of Chinggis Khan...
[1.2] It is here that the story begins:
[deger-e tngri] here deger-e is used as an adjective to form an adjectival phrase, lit. ‘high heaven’. This combined with -ece which puts the whole phrase into the ablative case, which as a whole qualifies the following de-verbal noun jayaghatu.
Translation: high heaven-from having been ordained/decreed
Gloss: Ordained from heaven above...
Misc. Note: tngri is used for both god/deity as well as heaven and sky. It apparently came into Mongolian by way of Uighur, along with its original Uighur spelling. However the roots of this word go very deep, and variations of it are found all over Asia (cf. Turkish ‘tener’, Tibetan ‘shangri’, Punjabi ‘Tengh’, it may possibly even be related to Chinese ‘Tien’). It can be traced back over 4000 years to the Sumerian word ‘dingir’.
[1.3]
[törügsen] This is a preterit participle. It is formed from the verb törü- + gsen and refers to an action completed in the past, and along with the copula a- qualifies the proper noun Börte Cinu-a. This is a good example of stylistic usage, the more usual form would be ‘Börte Cinu-a törügsen ajughu’ i.e. ‘Börte Cinu-a was born’ but it is displaced here to suit the rhythm of poetry.
Translation: having-been-born Börte Cinu-a was
Gloss: Börte Cinu-a was born...
[1.4]
[gergei inu] This possessive phrase is the predicate of this segment, consisting of a noun gergei and the generic pronoun inu which can refer to any person and any gender, and here refers back to the subject of [1.3] i.e. Börte Cinu-a.
[quva maral] is a proper noun and the subject.
[ajighai] is the copula.
Translation: wife-his Quva Maral was
Gloss: His wife was Quva Maral...
[1.5]
[tenggis] (proper noun) name of a large lake or sea. It is probably used here in the sense of ‘sea’ and might refer to lake Baikal.
[ketüljü] this is a converb and as such is dependant on the main verb, which in this case is the past-tense irebe.
Translation: (the)lake/sea (they)traversing/crossing went
Gloss: across the sea they went...
[1.6]
[onan müren-u terigün-e] this is a basic genitive phrase nested inside a dative-locative phrase.
Translation: onan river’s source/head-at
Gloss: at the source of the Onan river...
Section Translation:
No.1
Herein lies an account of the origins of Chinggis Khan...
Ordained from heaven above...
Börte Cinu-a was born.
His wife was Quva Maral.....
across the sea they went...
at Burqan-Qaldun they settled...
and there, their son Bataci-Qan was born.
No. 2
This is the account of the origin of Chinggis Khan.
The birth of Borte Chinu-a was ordained by heaven above. His wife was Quva Maral and having crossed the sea, they made their home at Burqan-Qaldun, near the source of the Onan river, and it was there that their son, Batci-Qan, was born.
