Mae heulwen gwan haf olaf yn taflu cysgodion tal dros garregau Cardiff Castell.

The weak sunlight of the last summer casts tall shadows over the stones of Cardiff Castell.

Y tir yn wyrdd a'r coed yn dechrau blodeuo oedd yn creu amgylchedd serene i Gareth a'i gefnder Tegan, a rhedodd i lawr y llwybr tywodlyd tuag at y mynedfa brif.

The ground was green and the trees beginning to bloom, creating a serene environment for Gareth and his cousin Tegan, who ran down the sandy path towards the main entrance.

"Mynd ymlaen brawd," Tegan yn gwenu, ond meiddiwyd ei ddihidio o dan wyneb hwylus, "dwi ddim yn deall pam wyt ti mor angerddol dros hon."

"Go on, brother," Tegan smiled, but she dared not disclose her true feelings beneath her playful exterior, "I don't understand why you're so passionate about this."

"Mae'n ein hanes ni, Tegan," atebodd Gareth, ei lais yn llawn cyffro. "Dwi'n teimlo ein bod yn byw mewn cysgod ein hen-achau, ond dydyn ni ddim yn gwybod pwy oedden nhw."

"It's our history, Tegan," replied Gareth, his voice full of excitement. "I feel like we're living in the shadow of our ancestors, but we don't know who they were."

Y ddau euog genedlaetholion, dyma hwy'n mynd i'r castell, wal i fyny lle mae golygfeydd dros einedd gwaelod o Gymru.

The two, feeling a sense of national pride, went into the castle, to the wall where there are views over the lower lands of Cymru.

Tegan a Gareth llithran lyn i'r archifdy, lle mae hen lyfrau a dogfennau yn cuddio.

Tegan and Gareth slipped into the archives, where old books and documents lie hidden.

"Wyt ti'n siŵr y gadawn ni fynd yma?" gofynnodd Tegan, ei llygaid yn chwilio am nefell tadog.

"Are you sure we'll be allowed in here?" asked Tegan, her eyes searching for any sign of disapproval.

"Bydd bod yn iawn," neilltuodd Gareth cyn iddo sôn wrth y swyddog archif am eu hymchwilwr hunan-benodedig. "Dwi wedi cael caniatâd arbennig," ychwanegodd.

"It'll be fine," Gareth assured her before speaking to the archive officer about their self-appointed research. "I have special permission," he added.

Ac yna, roeddent mewn, gafael ar ddogfennau sydd dipyn yn fwy na llyfrau ysgol oedd wedi'i meddiannu mensoldeb Gareth.

And then, they were there, holding documents much larger than school books that had captivated Gareth's imagination.

Ôl hanner ywan, sylwodd ddogfen hir ar drawsol gyda diwedd foel.

After a half-hour, he noticed a lengthy document with a bland ending.

"A dyma'r cregyn teulu," meddai Gareth, oherwydd ei bys yn symud gyda gwefredd dros lun lliwgar oedd yn cydweddu gyda'r hen-goffreistr o'u tref enedigol.

"And here's the family crest," said Gareth, as his finger moved excitedly over a colorful illustration that matched the old register of their hometown.

Pam mae ei hunan yn cyfrinachol, dyma fo'n ymladd gyda'i frawddegrwyd o brol, "Tegan, edrych! Mae'r cregyn ni 'ma."

While battling his own secrecy, he struggled with his speech of pride, "Look, Tegan! Here are our crests."

Am y tro cyntaf, roedd Tegan yn ddiarberth i ffeilio.

For the first time, Tegan was at a loss for words.

Cysgodun o amheuaeth yn rhannu ei gwefr a Gareth. "Felly... mae'r stori yn wir?" Cysgodd Tegan.

A shadow of doubt mingling with Gareth's thrill. "So... the story is true?" echoed Tegan.

"Oes, dwi'n cael tawelwch o wybod," atebodd Gareth, golygfa o benderfyniad dros ei lwydni i drallodus.

"Yes, I find peace in knowing," Gareth answered, a look of determination crossing his usually troubled expression.

Y ddau ymlaeng, y castell yn ol-golau a oedd yn disgyn gydag ego.

The two walked on, the castle bathed in afterglow, which descended with dignity.

Roedd y prynhawn iddyn nhw'n edrych fel bod yn adnewyddiad newydd o'u teulu.

The afternoon seemed like a new renewal of their family to them.

"Wel, dwi'n deall fy rôl yn awr," meddai Tegan ar y ffordd allan, yng ngolau euraid yr haul, "Mae'n bwysig gwybod o ble rydych chi'n dod."

"Well, I understand my role now," Tegan said on the way out, in the golden light of the sun, "It's important to know where you come from."

Aeth ymlaen i ddibynnu, a'r sefiad newydd un, gyda trylwywgariaeth nod a brwdfrydedd o'r awydd dysgu mwy am gor-ddiwedd hanes ei deulu.

She went on to commit, with a newfound knowledge and enthusiasm, the desire to learn more about the ancient history of her family.

Er bod Tegan dal yn geidwadol, yr hen feddyliar hynafol hyn oedd wedi'i wib-dirwedd.

Even though Tegan remained cautious, the old ancestral thoughts whirred through her mind.

A gyda hynny, daeth y cysynniad i deimlo, trwy ondennh.

And with that, the sense of feeling came, through the past.